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/*@ predicate sorted{L}(long *t, integer a, integer b) = @ \forall integer i,j; a <= i <= j <= b ==> t[i] <= t[j]; @*/ /*@ requires n >= 0 && \valid_range(t,0,n-1); @ ensures -1 <= \result < n; @ behavior success: @ ensures \result >= 0 ==> t[\result] == v; @ behavior failure: @ assumes sorted(t,0,n-1); @ ensures \result == -1 ==> @ \forall integer k; 0 <= k < n ==> t[k] != v; @*/ int binary_search(long t[], int n, long v) { int l = 0, u = n-1; /*@ loop invariant @ 0 <= l && u <= n-1; @ for failure: @ loop invariant @ \forall integer k; 0 <= k < n && t[k] == v ==> l <= k <= u; @ loop variant u-l; @*/ while (l <= u ) { int m = (l + u) / 2; //@ assert l <= m <= u; if (t[m] < v) l = m + 1; else if (t[m] > v) u = m - 1; else return m; } return -1; }
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//@ predicate is_pos(int x) = x > 0; //@ predicate is_nat(int x) = x >= 0; /*@ requires is_pos(x); ensures is_nat(\result); */ int minus1(int x) { return x-1; }
4
/*@ requires \valid(p); requires \valid(q); behavior p_changed: assumes n >0; assigns *p; ensures *p == n; behavior q_changed: assumes n <= 0; assigns *q; ensures *q == n; */ void f(int n, int *p, int *q) { if (n > 0) *p = n; else *q = n; }
10
/* run.config DONTRUN: linked with first which is the real test. */ /*@ behavior b: requires \valid(second); ensures \result == 0;*/ int bar(int *second); void sub (char * c) { bar(c); }
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// This program used an advanced ACSL clause: \max() // Note: Some versions of 'wp' plugin may not support the \lambda clause. // The program may not verify in every machine. /*@ requires n > 0; requires \valid_read(arr+(0..n-1)); ensures \result == \max(0, n-1, \lambda integer i; arr[i]); assigns \nothing; */ int array_max_advanced(int* arr, int n) { int max = arr[0]; for (int i = 0; i < n; i++) { if (arr[i] > max) { max = arr[i]; } } return max; }
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/*@ requires a_valid: \valid(a); requires b_valid: \valid(b); assigns *a, *b; ensures a_value: *a == \at(*b,Pre); ensures b_value: *b == \at(*a, Pre); */ void swap(int* a, int *b); /*@ requires a_valid: \valid(a); requires b_valid: \valid(b); requires c_valid: \valid(c); requires sep: \separated(a,b,c); ensures a_value: *a == \at(*b, Pre); ensures b_value: *b == \at(*c, Pre); ensures c_value: *c == \at(*a, Pre); */ void permut(int* a, int *b, int *c) { swap(a,b); swap(b,c); }
9
/*@ requires \valid(p); ensures \result == *p; */ int foo(int* p) { return *p; }
4
/* Software versions: frama-c : 18.0 (Argon) alt-ergo : 2.2.0 This script was run using this command: frama-c -wp -wp-prover alt-ergo -wp-rte -wp-timeout 300 -wp-verbose 0 countSameConsecutive.c -then -report */ // This predicate is true if there is a subsequence of length "answer" // with all its elements equal. /*@ predicate isValidAnswer(integer N, int *x, int answer) = @ \exists integer i; 0 <= i <= N-answer && @ (\forall integer j; i <= j <= i+answer-1 ==> x[j] == x[i]); @*/ // This predicate is true if there is no subsequence of length "answer+1" // with all its elements equal. /*@ @ predicate noBetterAnswerExists(integer N, int *x, int answer) = @ (N == answer) || @ ((1 <= answer < N) && (\forall integer i; 0 <= i <= N-1-answer ==> @ (\exists integer j; i < j <= i+answer && x[j] != x[i]))); @*/ /*@ @ predicate isBest(integer N, int *x, int answer) = @ isValidAnswer(N, x, answer) && @ noBetterAnswerExists(N, x, answer); @*/ /*@ requires 1 <= N <= 1000000; @ requires \valid(x + (0 .. N-1)); @ assigns \nothing; @ ensures isBest(N, x, \result); @*/ int countSameConsecutive(int N, int x[]) { int best = 0, i = 0; /*@ loop invariant 0 <= i <= N; @ loop invariant i == 0 ==> best == 0; @ loop invariant 0 < i <= N ==> isBest(i, x, best); @ loop invariant 0 < i < N ==> x[i] != x[i-1]; @ loop assigns i, best; @ loop variant N-i; @*/ while (i < N) { int j = i+1; /*@ loop invariant i+1 <= j <= N; @ loop invariant \forall integer k; i+1 <= k < j ==> x[i] == x[k]; @ loop assigns j; @ loop variant N-j; @*/ while (j < N && x[j] == x[i]) ++j; if (j-i > best) best = j-i; i = j; } return best; }
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/*@predicate who_is_taller{L}(int *x,integer j, integer last)= @ \forall integer i; j < i < last ==> x[j] > x[i]; @ */ /*@ predicate how_many{L}(int *x, integer counter, integer size,integer cnt) = @ (counter < size) ? @ (who_is_taller(x,counter,size))? how_many(x,counter+1,size,cnt-1) @ : how_many(x,counter+1,size,cnt) @ : cnt == 0; @*/ /*@ requires 0< N <= 1000000 ; @ requires \valid(x+(0..N-1)); @ requires \forall integer i; 0 <= i <= N-1 ==> 0< x[i] <= 1000000; @ ensures how_many(x,0,N,\result); @*/ int countWhoCanSee (int N, int x[]) { int tallest = x[N-1]; int count = 1; /*@ loop invariant -1 <= i < N-1; @ loop invariant 1 <= count < N-i; @ loop invariant \exists integer j; @ i<j<N && tallest==x[j]; @ loop invariant \forall integer j; @ i<j<N ==> tallest >=x[j]; @ loop invariant how_many(x,i+1,N,count); @ loop assigns i,count,tallest; @ loop variant i; @*/ for (int i = N-2; i >= 0; i--) if (tallest < x[i]) { tallest = x[i]; count++; } return count; }
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/*@ @ requires @ \valid(t + (0..size - 1)) && @ 0 <= i < size && @ 0 <= j < size; @ @ ensures @ \forall integer k; @ 0 <= k < size && k != i && k != j ==> @ t[k] == \old(t[k]); @ @ ensures @ t[i] == \old(t[j]) && @ t[j] == \old(t[i]); @ @ assigns @ t[i], t[j]; @ @*/ void swap(int t[], int size, int i, int j) { int tmp = t[i]; t[i] = t[j]; t[j] = tmp; }
10
/*@ensures\result == a &&\result>b || \result>a &&\result == b || \result == a &&\result == b;*/ int max(int a, int b) {return a>b ? a : b;}
3
#include <stddef.h> #include <stdio.h> /*@ predicate valid_range_rw(int* arr, integer n) = n >= 0 && \valid(arr + (0 .. n-1)); predicate valid_range_r(int* arr, integer n) = n >= 0 && \valid_read(arr + (0 .. n-1)); predicate sorted(int* arr, integer n) = \forall integer i, j; 0 <= i <= j < n ==> arr[i] <= arr[j]; predicate contains(int* arr, integer n, integer elem) = \exists integer off; 0 <= off < n && arr[off] == elem; */ /*@ requires valid_range_r(arr, len); requires sorted(arr, len); assigns \nothing; behavior in: assumes contains(arr, len, value); ensures arr[\result] == value; ensures 0 <= \result <= len-1; behavior notin: assumes !contains(arr, len, value); ensures \result == -1; disjoint behaviors; complete behaviors; */ int bsearch(int* arr, int len, int value){ if(len == 0) return -1 ; int low = 0 ; int up = len-1 ; /*@ loop invariant 0 <= low && up <= len-1; loop invariant \forall integer i; 0 <= i < low ==> arr[i] != value; loop invariant \forall integer i; up < i <= len-1 ==> arr[i] != value; loop assigns low, up; loop variant up - low; */ while(low <= up){ int mid = low + (up - low)/2 ; if (arr[mid] > value) up = mid-1 ; else if(arr[mid] < value) low = mid+1 ; else return mid ; } return -1 ; } int main(){ int i; int a[] = {1,2,3,4,5,6,7,8,9,10}; i = bsearch(a, 10, 3); //@ assert i == 2; i = bsearch(a, 10, 0); //@ assert i == -1; //printf("i = %d\n", i); return 0; }
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#include <string.h> /*@ requires strlen(input)>=0 && \valid(input+(0..strlen(input))); assigns \nothing; ensures \result==0 || \result==1; */ int dfa_aab(char* input) { if (*input == '\0') return 0/*false*/; int id = 0; char c; /*@ loop invariant strlen(input)>0 && \valid(input+(0..strlen(input))); loop invariant id == 6 || id == 3 || id == 0; loop assigns id, c, input; loop variant strlen(input); */ while (input[1] != '\0') { c = *input++; if (id == 0) { char x1 = c; int x2 = x1 == 'A'; int x16; if (x2) { x16 = 3; } else { x16 = 0; } id = x16; } else if (id == 6) { char x7 = c; int x8 = x7 == 'A'; int x13; if (x8) { x13 = 6; } else { x13 = 0; } id = x13; } else if (id == 3) { char x4 = c; int x5 = x4 == 'A'; int x14; if (x5) { x14 = 6; } else { x14 = 0; } id = x14; } else { return -1; /*error: invalid state*/ } } c = *input; if (id == 0) { char x1 = c; int x2 = x1 == 'A'; int x16; if (x2) { x16 = 0/*false*/; } else { x16 = 0/*false*/; } id = x16; } else if (id == 6) { char x7 = c; int x8 = x7 == 'A'; int x13; if (x8) { x13 = 0/*false*/; } else { x13 = 1/*true*/; } id = x13; } else if (id == 3) { char x4 = c; int x5 = x4 == 'A'; int x14; if (x5) { x14 = 0/*false*/; } else { x14 = 0/*false*/; } id = x14; } else { return -1; /*error: invalid state */ } return id; }
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/* @ requires \valid(t+(start..end)) && start <= i <= end && start <= j <= end */ void swap(int t[], int i, int j, int start, int end) { int tmp = t[i]; t[i] = t[j]; t[j] = tmp; } /*@ requires 0 <= p <= r && \valid(A+(p..r)); @*/ int partition (int A[], int p, int r) { int x = A[r]; int j, i = p-1; /*@ loop invariant p <= j <= r && p-1 <= i < j; @ loop assigns i, j, A[p..r]; @ loop variant r-j; @*/ for (j=p; j<r; j++) if (A[j] <= x) { i++; swap(A, i, j, p, r); } swap(A,i+1,r,p,r); return i+1; }
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#define HASHTBL_LEN 17 typedef struct { int b; int size; } Buckets; typedef struct { Buckets data[HASHTBL_LEN]; int size; } Hashtbl; /*@ requires \valid(tbl); @ requires \valid(tbl->data+(0 .. HASHTBL_LEN - 1)); @ requires 0 <= d < HASHTBL_LEN; @ @ assigns tbl->data[d], tbl->size; // approximation sur tbl->data[d]; si on écrit tbl->data[d].size, pas de problème @ */ int add(Hashtbl *tbl, int d) { unsigned int h = d; tbl->data[h].size = 0; // si on inline d, pas de probleme tbl->size = 0; return 0; }
8
#include<stdio.h> #include<limits.h> /*@ requires x>=0; ensures \result == x*x*x; */ int p2(int x){ int z=0,v=0,w=1,t=3,u=0; /*@ loop invariant u<=x && t==6*u+3 && w==3*u+1 && v==3*u*u && z==u*u*u; loop assigns z,v,t,w,u;*/ while ( u <= x ){ z=z+v+w; v=v+t ; t = t+6; w=w+3; u=u+1; } //@ assert u==x; //@ assert z==x*x*x; return ( z ) ; } int main (){ int v,r; printf("Entrez la valeur pour v : " ); scanf ("%d",&v); r=v*v*v; printf( "voici la réponse de votre solution p2(%d)=%d et devrait valeur %d\n ",v,p2(v),r); return 0 ; }
8
// Version 2: Better specification #include <limits.h> /*@ requires x > INT_MIN; behavior positive: assumes x > 0; ensures \result == \old(x); behavior negative: assumes x < 0; ensures \result == \old(-x); */ int abs(int x) { if (x < 0) return -x; else return x; } int main() { abs(10); abs(-20); return 0; }
9
/*@ requires \valid(a) && \valid_read(b); requires \separated(a, b); assigns *a; ensures *a == \old(*a) + *b; ensures *b == \old(*b); */ int incr_a_by_b(int* a, int const* b){ *a += *b; return *a; }
9
/*@ requires n>0; requires\valid_read(arr + (0..n-1)); */ void cummilativeSum(int arr[], int n) { int sum = 0, prev = 0, j, x; /*@ loop invariant \exists integer i; 0 <= i < n ==> arr[j] == prev + arr[i]; loop invariant 0 <= j <= n; loop assigns j, arr[0..j+1], prev; loop variant n-j; */ for (j = 0; j < n; j++) { arr[j] = prev + arr[j]; prev = arr[j]; } }
9
/*@ predicate sorted{L}(int* a, integer length) = \forall integer i,j; 0<=i<=j<length ==> a[i]<=a[j]; */ /*@ requires \valid(a+(0..length-1)); requires length > 0; assigns a[0..length-1]; ensures sorted(a,length); */ void sort (int* a, int length) { int current; /*@ loop invariant 0<=current<length; loop assigns a[0..length-1],current; loop invariant sorted(a,current); loop invariant \forall integer i,j; 0<=i<current<=j<length ==> a[i] <= a[j]; loop variant length-current; */ for (current = 0; current < length - 1; current++) { int min_idx = current; int min = a[current]; /*@ loop invariant current+1<=i<=length; loop assigns i,min,min_idx; loop invariant current<=min_idx<i; loop invariant a[min_idx] == min; loop invariant \forall integer j; current<=j<i ==> min <= a[j]; loop variant length -i; */ for (int i = current + 1; i < length; i++) { if (a[i] < min) { min = a[i]; min_idx = i; } } if(min_idx != current) { L: a[min_idx]=a[current]; a[current]=min; } } }
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/*@ requires a!=0; ensures \result == 1; assigns \nothing; */ int func(int a) { int x, y; int sum, res; if (a == 0){ x = 0; y = 0; } else { x = 5; y = 5; } sum = x + y; res = 10/sum; return res; }
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/*@ requires \true; assigns \nothing; ensures \result == b; */ int deadcode(int a, int b) { if (a > b) { if (a < b) { return a / b; } else if (a == b) { //@ assert 0 == 1; } } return b; }
8
#include<limits.h> /*@ ensures \result >= a && \result >= b; */ int max ( int a, int b ) { return INT_MAX ; }
3
/*@ @ assigns \nothing; @ ensures \result <= a; @ ensures \result <= b; @ ensures \result == a || \result == b; */ int min(int a, int b) { return (a < b) ? a : b; }
7
#include <stddef.h> /*@ predicate monotone_slice(int* a, size_t low, size_t up) = (\forall integer i,j; low <= i < j < up ==> a[i] < a[j]) || (\forall integer i,j; low <= i <= j < up ==> a[i] >= a[j]); */ /*@ requires length < 100; requires a_valid: \valid(a + (0 .. length - 1)); requires res_valid: \valid(cutpoints + (0 .. length)); requires sep: \separated(a + (0 .. length - 1), cutpoints + (0 .. length)); assigns cutpoints[0 .. length]; ensures pos: \result > 0; ensures beg: cutpoints[0] == 0; ensures end: cutpoints[\result - 1] == length; ensures bounds: \forall integer i; 0 <= i < \result ==> 0<= cutpoints[i] <= length; ensures monotonic: \forall integer i; 0 <= i < \result - 1 ==> monotone_slice(a,cutpoints[i],cutpoints[i+1]); */ size_t monotonic(int* a, size_t length, size_t* cutpoints) { cutpoints[0] = 0; if (length == 0) return 1; size_t x = 0, y = 1; size_t res = 1; /*@ loop invariant outer_bound: 1 <= y <= length; loop invariant x_1: y < length ==> x == y - 1; loop invariant x_2: y == length ==> x == y - 1 || x == y; loop invariant monotone: \forall integer i; 0 <= i < res - 1 ==> monotone_slice(a,cutpoints[i],cutpoints[i+1]); loop invariant res_bounds: 1 <= res <= y; loop invariant content_bounds: \forall integer i; 0 <= i < res ==> 0<= cutpoints[i] <= length; loop invariant cuts_increase: \forall integer i, j; 0 <= i <= j < res ==> cutpoints[i] <= cutpoints[j]; loop invariant last_write: cutpoints[res - 1] == x; loop assigns x,y,res,cutpoints[1 .. length]; loop variant length - y; */ while (y < length) { int increasing = a[x] < a[y]; /*@ loop invariant inner_bound: x + 1 <= y <= length; loop invariant res_low: res <= y; loop invariant mono_slice_1: increasing ==> \forall integer i, j; x <= i < j < y ==> a[i] < a[j]; loop invariant mono_slice_2: (!increasing) ==> \forall integer i, j; x <= i <= j < y ==> a[i] >= a[j]; loop assigns y; loop variant length - y; */ while (y < length && (a[y-1] < a[y]) == increasing) y++; /*@ assert mono: monotone_slice(a,x,y); */ cutpoints[res] = y; res++; /*@ assert mono_res: monotone_slice(a,cutpoints[res-2],cutpoints[res-1]);*/ x = y; if (y < length) y++; } if (x < length) { /*@ assert last: x == length - 1; */ /*@ assert mono_2: monotone_slice(a,x,length); */ cutpoints[res] = length; res++; /*@ assert mono_3: monotone_slice(a,cutpoints[res - 2], cutpoints[res - 1]); */ } return res; }
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/*@ requires \valid(a) && \valid(b); assigns *a, *b; ensures (*a) == \old(*b); ensures (*b) == \old(*a); */ void foo(int* a, int* b) { int tmp = *a; *a = *b; *b = tmp; }
10
/*@requires a>0 && a<2147483647; ensures\result>1;*/ int next(int a) {return a + 1;}
4
/*@ predicate swapped {L1, L2}(int* a, int* b) = \at(*a, L1) == \at(*b, L2) && \at(*b, L1) == \at(*a, L2); */ /*@ requires \valid(a); requires \valid(b); assigns *a; assigns *b; ensures *a == \old(*b); ensures *b == \old(*a); ensures swapped{Here, Old}(a,b); */ void swap (int* a, int* b ) { int c = *a; *a = *b; *b = c; }
11
#include <stdio.h> /*@ requires \valid(a+(0..n-1)); requires n > 0; ensures \forall integer i,j; 0<=i<=j<=n-1 ==> a[i]<=a[j]; */ void bubbleSort(int *a, int n) { int i, j, temp; /*@ loop invariant \forall integer p,q; i<=p<=q<=n-1 ==> a[p]<=a[q]; loop invariant \forall integer p,q; 0<=p<i+1==q<=n-1 ==> a[p]<=a[q]; loop invariant 0<=i<n; loop assigns i,j,temp,a[0..n-1]; loop variant i; */ for(i=n-1; i>0; i--) { /*@ loop invariant 0<=j<=i<n; loop invariant \forall integer k; 0<=k<=j ==> a[k] <= a[j]; loop invariant \forall integer p, q; 0<=p<i+1==q<=n-1 ==> a[p]<=a[q]; loop assigns j,temp,a[0..i]; loop variant i-j; */ for(j=0; j<i; j++) { if (a[j] > a[j+1]) { temp = a[j]; a[j] = a[j+1]; a[j+1] = temp; } } } }
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/* * Frama-C version: Sulfur-20171101 * Alt-Ergo version: 1.30 * * Run with: * frama-c -wp -wp-prover alt-ergo -wp-rte -wp-timeout 10 -wp-verbose 0 find-double.c -then -report * */ #include <stdbool.h> #define MAXV 1000000 /*@ predicate doublesInside(integer N, int* a, integer res) = @ \exists integer ii; \exists integer jj; @ 0 <= ii < N && 0 <= jj < N && ii != jj ==> a[ii] == a[jj] == res; @*/ /*@ predicate noDoublesInside(integer N, int* a) = @ \forall integer ii; \forall integer jj; @ 0 <= ii < N && 0 <= jj < N && ii != jj ==> a[ii] != a[jj]; @*/ /*@ predicate doublesFound(integer N, int* a, integer res) = @ (res > 0) ? doublesInside(N, a, res) : noDoublesInside(N, a); @*/ /*@ requires 1 <= N <= MAXV; @ requires \valid(a + (0..N-1)); @ requires \forall integer p; 0 <= p < N ==> 1 <= a[p] <= MAXV; @ ensures doublesFound(N, a, \result); @*/ int findDouble(int N, int a[]) { bool f[MAXV]; /*@ loop invariant 1 <= i <= MAXV+1; @ loop invariant \forall integer p; 1 <= p < i ==> f[p-1] == false; @ loop assigns i, f[0..(MAXV-1)]; @ loop variant MAXV - i; @*/ for (int i = 1; i <= MAXV; ++i) f[i-1] = false; /*@ loop invariant 0 <= i <= N; @ loop invariant \forall integer p; 0 <= p < i ==> f[a[p]-1] != false; @ loop invariant noDoublesInside(i, a); @ loop assigns i, f[0..(MAXV-1)]; @ loop variant N - i; @*/ for (int i = 0; i < N; ++i) if (f[a[i]-1]) return a[i]; else f[a[i]-1] = true; return 0; }
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/*@ requires size >= 0; requires \valid(a+(0..size-1)); requires \valid(res+(0..size-1)); assigns res[0..size-1]; ensures \forall integer i; 0 <= i < size ==> res[i] == a[size - i - 1]; */ void reverse(int a[], int res[], int size) { int i; /*@ loop invariant -1 <= i < size; //Найдите ошибку loop invariant \forall integer j; i < j < size ==> res[j] == a[size - j - 1]; loop assigns i, res[0..size-1]; loop variant i; */ for(i = size - 1; i >= 0; --i) { res[i] = a[size - i - 1]; } } #ifdef OUT_OF_TASK #include <stdio.h> int main(void) { int a[] = {1,2,3,4,5,6,7,8,9,10}; int size = sizeof(a) / sizeof(a[0]); int b[size]; for(int i = 0; i < size; ++i) { printf("%d ", a[i]); } printf("\n"); reverse(a, b, size); for(int i = 0; i < size; ++i) { printf("%d ", b[i]); } printf("\n"); } #endif
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/*@ predicate Swap{L1,L2}(int *a, integer i, integer j) = @ \at(a[i],L1) == \at(a[j],L2) && @ \at(a[j],L1) == \at(a[i],L2) ; @*/ /*@ inductive Permuta{L1,L2}(int *a, integer l, integer h) { @ case Permut_refl{L}: @ \forall int *a, integer l, h; Permuta{L,L}(a, l, h) ; @ case Permut_sym{L1,L2}: @ \forall int *a, integer l, h; @ Permuta{L1,L2}(a, l, h) ==> Permuta{L2,L1}(a, l, h) ; @ case Permut_trans{L1,L2,L3}: @ \forall int *a, integer l, h; @ Permuta{L1,L2}(a, l, h) && Permuta{L2,L3}(a, l, h) ==> @ Permuta{L1,L3}(a, l, h) ; @ case Permut_swap{L1,L2}: @ \forall int *a, integer l, h, i, j; @ l <= i <= h && l <= j <= h && Swap{L1,L2}(a, i, j) ==> @ Permuta{L1,L2}(a, l, h) ; @ } @*/ /*@ requires \valid(t+(start..end)) && start <= i <= end && start <= j <= end; @ ensures Swap{Old,Here}(t,i,j); @ assigns t[i],t[j]; @*/ void swap(int t[],int i,int j, int start, int end) { int tmp = t[i]; t[i] = t[j]; t[j] = tmp; } /*@ requires 0 <= p <= r && \valid(A+(p..r)); @ assigns A[p..r]; @ behavior partition: @ ensures @ p <= \result <= r && @ (\forall int l; p <= l < \result ==> A[l] <= A[\result]) && @ (\forall int l; \result < l <= r ==> A[l] > A[\result]) && @ A[\result] == \old(A[r]) ; @ behavior permutation: @ ensures @ Permuta{Old,Here}(A,p,r); @*/ int partition (int A[], int p, int r) { int x = A[r]; int j, i = p-1; /*@ loop invariant @ p <= j <= r && p-1 <= i < j; @ loop assigns i, j, A[p..r-1]; @ for partition: @ loop invariant @ (\forall int k; (p <= k <= i) ==> A[k] <= x) && @ (\forall int k; (i < k < j) ==> A[k] > x) && @ A[r] == x; @ for permutation: @ loop invariant @ Permuta{Pre,Here}(A,p,r); @ loop variant (r-j); @*/ for (j=p; j<r; j++) if (A[j] <= x) { i++; swap(A,i,j,p,r); } swap(A,i+1,r,p,r); return i+1; }
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/*@ assigns \nothing; ensures \result == (a+b)/2; */ int average(int a, int b) { int average = 0; int greater; int smaller; if (a > b) { greater = a; smaller = b; } else { greater = b; smaller = a; } if (a >= 0 && b >= 0) { average = smaller + (greater - smaller) / 2; } else if (a < 0 && b < 0) { average = greater + (smaller - greater) / 2; } else if ((a >= 0 && b <= 0) || (a <= 0 && b >= 0)) { average = (a + b) / 2; } return average; } #ifdef OUT_OF_TASK #include <stdio.h> int main(void) { printf("res: %d\n", average(3,30)); printf("res: %d\n", average(-5,-20)); printf("res: %d\n", average(7,-10)); printf("res: %d\n", average(-2,15)); return 0; } #endif
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#define INT_MIN (-2147483648) #define INT_MAX 2147483647 /*@ requires INT_MIN <= a + b <= INT_MAX; assigns \nothing; ensures \result == a + b; */ int sum(int a, int b) { return a + b; }
6
#include <limits.h> struct A { unsigned int size; unsigned int pos; }; typedef struct A A; /*@ requires \valid(a); requires length <= 64; requires a->pos + length <= UINT_MAX; requires a->pos + length <= a->size; assigns a->pos; ensures a->pos == \old(a->pos) + length; */ void foo(A* a, unsigned int length) { a->pos += length; } /*@ requires \valid(a); requires length <= 64; requires a->pos + length <= UINT_MAX; requires a->pos + length <= a->size; assigns a->pos; ensures a->pos == \old(a->pos) + length; */ void bar(A* a, unsigned int length) { foo(a, length); a->pos -= length; foo(a, length); }
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/*@ requires \valid(&a[i]); requires \valid(&a[j]); assigns a[i], a[j]; ensures a[i] == \old(a[j]); ensures a[j] == \old(a[i]); */ void swap(int a[], int i, int j) #ifndef OUT_OF_TASK ; #else { int tmp = a[i]; a[i] = a[j]; a[j] = tmp; } #endif /*@ predicate reverse{L1,L2}(int* a, integer size, integer i, integer j) = \forall integer k; i <= k < j ==> \at(a[k], L1) == \at(a[size - k - 1], L2); predicate reverse{L1,L2}(int* a, integer size) = reverse{L1,L2}(a, size, 0, size); */ /*@ requires size >= 0; requires \valid(a+(0..size-1)); assigns a[0..size-1]; ensures reverse{Pre,Here}(a, size); ensures \forall integer i; 0 <= i < size ==> \exists integer j; 0 <= j < size && \old(a[\at(i,Here)]) == a[j]; */ void reverse_in_place(int a[], int size) { int i; /*@ loop invariant 0 <= i <= size / 2; loop invariant reverse{Pre,Here}(a, size, 0, i); loop invariant \forall integer j; i <= j < size - i ==> a[j] == \at(a[\at(j,Here)],Pre); loop invariant reverse{Pre,Here}(a, size, size - i, size); loop assigns i, a[0..size-1]; loop variant size / 2 - i; */ for(i = 0; i < (size / 2); ++i) { swap(a, i, size - i - 1); } } #ifdef OUT_OF_TASK #include <stdio.h> int main(void) { int a[] = {1,2,3,4,5,6,7,8,9,10}; int size = sizeof(a) / sizeof(a[0]); for(int i = 0; i < size; ++i) { printf("%d ", a[i]); } printf("\n"); reverse_in_place(a, size); for(int i = 0; i < size; ++i) { printf("%d ", a[i]); } printf("\n"); } #endif
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/*@ assigns \nothing; ensures \result >= a; ensures \result >= b; ensures \result == a || \result == b; */ int max(int a, int b) { return a > b ? a : b; }
7
/*@ requires n>0; behavior one: assumes n>0; ensures \result == n; behavior two: assumes n<0; ensures \result == (-1)*n; complete behaviors; disjoint behaviors; */ int ABS(int n) { if (n < 0) { n = (-1) * n; } return n; }
8
/*@ predicate sorted{L}(int* a, integer length) = \forall integer i,j; 0<=i<=j<length ==> a[i]<=a[j]; */ /*@ predicate swap{L1,L2}(int* a,integer i,integer j,integer length)= 0<=i<j<length && \at(a[i],L1) == \at(a[j],L2) && \at(a[i],L2) == \at(a[j],L1) && \forall integer k; 0<=k<length && k!=i && k!=j ==> \at(a[k],L1) == \at(a[k],L2); */ /*@ inductive same_elements{L1,L2}(int*a , integer length) { case refl{L}: \forall int*a, integer length; same_elements{L,L}(a,length); case swap{L1,L2}: \forall int*a, integer i,j,length; swap{L1,L2}(a,i,j,length) ==> same_elements{L1,L2}(a,length); case trans{L1,L2,L3}: \forall int*a, integer length; same_elements{L1,L2}(a,length) ==> same_elements{L2,L3}(a,length) ==> same_elements{L1,L3}(a,length); } */ /*@ requires valid_array: \valid(a+(0..length-1)); requires non_empty: length > 0; assigns a[0..length-1]; behavior sorted: ensures sorted(a,length); behavior same_elements: ensures same_elements{Pre,Here}(a,length); */ void sort (int* a, int length) { int current; /*@ loop invariant outer_bounds: 0<=current<length; loop assigns a[0..length-1],current; for sorted: loop invariant begin_sort: sorted(a,current); for sorted: loop invariant tail_bigger: \forall integer i,j; 0<=i<current<=j<length ==> a[i] <= a[j]; for same_elements: loop invariant same_elements{Pre,Here}(a,length); loop variant length-current; */ for (current = 0; current < length - 1; current++) { int min_idx = current; int min = a[current]; /*@ loop invariant inner_bounds: current+1<=i<=length; loop assigns i,min,min_idx; loop invariant min_idx_bounds: current<=min_idx<i; loop invariant min_idx_val: a[min_idx] == min; for sorted: loop invariant min_idx_min: \forall integer j; current<=j<i ==> min <= a[j]; loop variant length -i; */ for (int i = current + 1; i < length; i++) { if (a[i] < min) { min = a[i]; min_idx = i; } } if(min_idx != current) { L: a[min_idx]=a[current]; a[current]=min; /*@ for same_elements: assert swap: swap{L,Here}(a,current,min_idx,length); */ } } }
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// remplir un tableau avec une valeur donnée /*@ requires \valid (t+(0..n-1)); requires n > 0; assigns t[0..n-1]; ensures \forall integer i; 0 <= i < n ==> t[i] == val; */ void fill_array(int t[], int n, int val) { int i = 0; /*@ loop invariant \forall integer j; 0 <= j < i ==> t[j] == val; loop invariant 0 <= i <= n; loop variant n-i; */ while (i < n) { t[i] = val; i++; } }
43
#include <limits.h> /*@ requires INT_MIN<x && INT_MIN<y; ensures \result>=x && \result>=y; ensures \result==x || \result==y; */ int max ( int x, int y ) { if ( x >=y ) return x ; return y ; } void foo() { int s = max(34,45); int t = max(-43,34); }
8
/* Run with: * * frama-c -wp -wp-prover alt-ergo -wp-rte -wp-timeout 60 -wp-verbose 0 samenum.c -then -report * * Tested with Frama-C Phosphorus-20170501. */ #define MAXN 1000000 #define MAXV 2000000 /*@ predicate isPair{L}(integer N, int* x, integer i, integer j) = @ 0 <= i < j < N && \at(x[i], L) == \at(x[j], L); @*/ /*@ predicate existsPair{L}(integer N, int* x) = @ \exists integer i, j; 0 <= i < j < N && \at(x[i], L) == \at(x[j], L); @*/ /*@ predicate isValidSolution{L}(integer N, int* x, integer r) = @ existsPair{L}(N, x) ? @ (\exists integer i, j; 0 <= i < j < N && \at(x[i], L) == \at(x[j], L) ==> r == j - i) && @ (\forall integer n, m; 0 <= n < m < N && \at(x[n], L) == \at(x[m], L) ==> r >= m - n) @ : r == 0; @*/ /*@ requires 0 <= N <= MAXN; @ requires \valid(x + (0..N-1)); @ requires \forall integer j; 0 <= j < N ==> 0 <= x[j] <= MAXV; @ ensures isValidSolution(N, x, \result); @*/ int samenum(int N, int *x) { int p[MAXV+1]; /*@ loop invariant 0 <= i <= MAXV+1; @ loop invariant \forall integer j; 0 <= j < i ==> p[j] == -1; @ loop assigns i, p[0 .. MAXV]; @ loop variant MAXV - i; @*/ for (int i = 0; i <= MAXV; ++i) p[i] = -1; int best = 0; /*@ loop invariant 0 <= i <= N; @ loop invariant \forall integer j; i <= j < N ==> p[x[j]] >= -1; @ loop invariant \forall integer j; 0 <= j < i ==> (best >= j - p[x[j]] || p[x[j]] == j); @ loop invariant best >= 0; @ loop invariant \forall integer j; 0 <= j <= MAXV && p[j] >= 0 <==> (\exists integer k; 0 <= k < i && x[k] == j); @ loop invariant \forall integer j, k; 0 <= k <= j < i && x[j] == x[k] ==> p[x[j]] <= k; @ loop invariant isValidSolution(i, x, best); @ loop assigns i, best, p[0 .. MAXV]; @ loop variant N - i; @*/ for (int i = 0; i < N; ++i) { if (p[x[i]] == -1) p[x[i]] = i; else if (i-p[x[i]] > best) best = i-p[x[i]]; } return best; }
47
/*@ requires \valid(&a[i]); requires \valid(&a[j]); assigns a[i], a[j]; ensures a[i] == \old(a[j]); ensures a[j] == \old(a[i]); */ void swap(int a[], int i, int j); /*@ predicate reverse{L1,L2}(int* a, integer size, integer i, integer j) = \forall integer k; i <= k < j ==> \at(a[k], L1) == \at(a[size - k - 1], L2); predicate reverse{L1,L2}(int* a, integer size) = reverse{L1,L2}(a, size, 0, size); */ /*@ requires size >= 0; requires \valid(a+(0..size-1)); assigns a[0..size-1]; ensures reverse{Pre,Here}(a, size); ensures \forall integer i; 0 <= i < size ==> \exists integer j; 0 <= j < size && \old(a[\at(i,Here)]) == a[j]; */ void reverse_in_place(int a[], int size) { int i; /*@ loop invariant 0 <= i <= size / 2; loop invariant reverse{Pre,Here}(a, size, 0, i); loop invariant \forall integer j; i <= j < size - i ==> a[j] == \at(a[\at(j,Here)],Pre); loop invariant reverse{Pre,Here}(a, size, size - i, size); loop assigns i, a[0..size-1]; loop variant size / 2 - i; */ for(i = 0; i < (size / 2); ++i) { swap(a, i, size - i - 1); } }
28
#include <limits.h> /*@ requires x < INT_MAX; ensures \result > x; */ int inc (int x) { return x+1; }
4
#include <limits.h> #include <string.h> /*@ predicate star_A(char * x93, integer x94, integer x95) = ((x94==x95) || (\exists integer x98; (((x94<x98) && (x98<=x95)) ==> ((('A'==x93[x94]) && (x98==(x94+1))) && star_A(x93,x98,x95)))));*/ /*@ predicate star_D(char * x114, integer x115, integer x116) = ((x115==x116) || (\exists integer x119; (((x115<x119) && (x119<=x116)) ==> ((('D'==x114[x115]) && (x119==(x115+1))) && star_D(x114,x119,x116)))));*/ /*@ predicate star_C(char * x135, integer x136, integer x137) = ((x136==x137) || (\exists integer x140; (((x136<x140) && (x140<=x137)) ==> ((('C'==x135[x136]) && (x140==(x136+1))) && star_C(x135,x140,x137)))));*/ /*@ predicate star__orB_or_C_sCs_Bor_(char * x156, integer x157, integer x158) = ((x157==x158) || (\exists integer x161; (((x157<x161) && (x161<=x158)) ==> (((('B'==x156[x157]) && (x161==(x157+1))) || (\exists integer x170; ((((x157<=x170) && (x170<=x161)) && (('C'==x156[x157]) && (x170==(x157+1)))) && (\exists integer x178; ((((x170<=x178) && (x178<=x161)) && star_C(x156,x170,x178)) && (('B'==x156[x178]) && (x161==(x178+1)))))))) && star__orB_or_C_sCs_Bor_(x156,x161,x158)))));*/ /*@ predicate re_0(char * x0, integer x1, integer x2) = (\exists integer x4; ((((x1<=x4) && (x4<=x2)) && (('A'==x0[x1]) && (x4==(x1+1)))) && (\exists integer x14; ((((x4<=x14) && (x14<=x2)) && star_A(x0,x4,x14)) && (\exists integer x21; ((((x14<=x21) && (x21<=x2)) && (('B'==x0[x14]) && (x21==(x14+1)))) && (\exists integer x31; ((((x21<=x31) && (x31<=x2)) && star__orB_or_C_sCs_Bor_(x0,x21,x31)) && (\exists integer x38; ((((x31<=x38) && (x38<=x2)) && (('C'==x0[x31]) && (x38==(x31+1)))) && (\exists integer x48; ((((x38<=x48) && (x48<=x2)) && star_C(x0,x38,x48)) && (\exists integer x55; ((((x48<=x55) && (x55<=x2)) && (('D'==x0[x48]) && (x55==(x48+1)))) && (\exists integer x65; ((((x55<=x65) && (x65<=x2)) && star_D(x0,x55,x65)) && (x65==x2)))))))))))))))));*/ /*@ predicate re_1(char * x201, integer x202, integer x203) = (\exists integer x205; ((((x202<=x205) && (x205<=x203)) && star_A(x201,x202,x205)) && (\exists integer x211; ((((x205<=x211) && (x211<=x203)) && (('B'==x201[x205]) && (x211==(x205+1)))) && (\exists integer x221; ((((x211<=x221) && (x221<=x203)) && star__orB_or_C_sCs_Bor_(x201,x211,x221)) && (\exists integer x227; ((((x221<=x227) && (x227<=x203)) && (('C'==x201[x221]) && (x227==(x221+1)))) && (\exists integer x237; ((((x227<=x237) && (x237<=x203)) && star_C(x201,x227,x237)) && (\exists integer x243; ((((x237<=x243) && (x243<=x203)) && (('D'==x201[x237]) && (x243==(x237+1)))) && (\exists integer x253; ((((x243<=x253) && (x253<=x203)) && star_D(x201,x243,x253)) && (x253==x203)))))))))))))));*/ /*@ predicate re_2(char * x274, integer x275, integer x276) = (\exists integer x278; ((((x275<=x278) && (x278<=x276)) && star__orB_or_C_sCs_Bor_(x274,x275,x278)) && (\exists integer x284; ((((x278<=x284) && (x284<=x276)) && (('C'==x274[x278]) && (x284==(x278+1)))) && (\exists integer x294; ((((x284<=x294) && (x294<=x276)) && star_C(x274,x284,x294)) && (\exists integer x300; ((((x294<=x300) && (x300<=x276)) && (('D'==x274[x294]) && (x300==(x294+1)))) && (\exists integer x310; ((((x300<=x310) && (x310<=x276)) && star_D(x274,x300,x310)) && (x310==x276)))))))))));*/ /*@ predicate re_3(char * x327, integer x328, integer x329) = (\exists integer x331; ((((x328<=x331) && (x331<=x329)) && star_C(x327,x328,x331)) && (\exists integer x337; ((((x331<=x337) && (x337<=x329)) && (('D'==x327[x331]) && (x337==(x331+1)))) && (\exists integer x347; ((((x337<=x347) && (x347<=x329)) && star_D(x327,x337,x347)) && (x347==x329)))))));*/ /*@ predicate re_4(char * x360, integer x361, integer x362) = (\exists integer x364; ((((x361<=x364) && (x364<=x362)) && star_D(x360,x361,x364)) && (x364==x362)));*/ /*@ predicate re_bwd_0(char * x373, integer x374, integer x375) = (x374==x375);*/ /*@ predicate re_bwd_1(char * x378, integer x379, integer x380) = (\exists integer x382; ((((x379<=x382) && (x382<=x380)) && (('A'==x378[x379]) && (x382==(x379+1)))) && (\exists integer x392; ((((x382<=x392) && (x392<=x380)) && star_A(x378,x382,x392)) && (x392==x380)))));*/ /*@ predicate re_bwd_2(char * x403, integer x404, integer x405) = (\exists integer x407; ((((x404<=x407) && (x407<=x405)) && (('A'==x403[x404]) && (x407==(x404+1)))) && (\exists integer x417; ((((x407<=x417) && (x417<=x405)) && star_A(x403,x407,x417)) && (\exists integer x423; ((((x417<=x423) && (x423<=x405)) && (('B'==x403[x417]) && (x423==(x417+1)))) && (\exists integer x433; ((((x423<=x433) && (x433<=x405)) && star__orB_or_C_sCs_Bor_(x403,x423,x433)) && (x433==x405)))))))));*/ /*@ predicate re_bwd_3(char * x448, integer x449, integer x450) = (\exists integer x452; ((((x449<=x452) && (x452<=x450)) && (('A'==x448[x449]) && (x452==(x449+1)))) && (\exists integer x462; ((((x452<=x462) && (x462<=x450)) && star_A(x448,x452,x462)) && (\exists integer x468; ((((x462<=x468) && (x468<=x450)) && (('B'==x448[x462]) && (x468==(x462+1)))) && (\exists integer x478; ((((x468<=x478) && (x478<=x450)) && star__orB_or_C_sCs_Bor_(x448,x468,x478)) && (\exists integer x484; ((((x478<=x484) && (x484<=x450)) && (('C'==x448[x478]) && (x484==(x478+1)))) && (\exists integer x494; ((((x484<=x494) && (x494<=x450)) && star_C(x448,x484,x494)) && (x494==x450)))))))))))));*/ /*@ predicate re_bwd_4(char * x513, integer x514, integer x515) = (\exists integer x517; ((((x514<=x517) && (x517<=x515)) && (('A'==x513[x514]) && (x517==(x514+1)))) && (\exists integer x527; ((((x517<=x527) && (x527<=x515)) && star_A(x513,x517,x527)) && (\exists integer x533; ((((x527<=x533) && (x533<=x515)) && (('B'==x513[x527]) && (x533==(x527+1)))) && (\exists integer x543; ((((x533<=x543) && (x543<=x515)) && star__orB_or_C_sCs_Bor_(x513,x533,x543)) && (\exists integer x549; ((((x543<=x549) && (x549<=x515)) && (('C'==x513[x543]) && (x549==(x543+1)))) && (\exists integer x559; ((((x549<=x559) && (x559<=x515)) && star_C(x513,x549,x559)) && (\exists integer x565; ((((x559<=x565) && (x565<=x515)) && (('D'==x513[x559]) && (x565==(x559+1)))) && (\exists integer x575; ((((x565<=x575) && (x575<=x515)) && star_D(x513,x565,x575)) && (x575==x515)))))))))))))))));*/ /*@ predicate star_starting_D(char * x719, integer x720, integer x721) = ((((x720==x721) || (('D'==x719[x720]) && (x721>=(x720+1)))) || (\exists integer x730; (((x720<x730) && (x730<=x721)) ==> ((('D'==x719[x720]) && (x730==(x720+1))) && star_starting_D(x719,x730,x721))))) || (x721>=x720));*/ /*@ predicate star_starting_A(char * x745, integer x746, integer x747) = ((((x746==x747) || (('A'==x745[x746]) && (x747>=(x746+1)))) || (\exists integer x756; (((x746<x756) && (x756<=x747)) ==> ((('A'==x745[x746]) && (x756==(x746+1))) && star_starting_A(x745,x756,x747))))) || (x747>=x746));*/ /*@ predicate star_starting_C(char * x771, integer x772, integer x773) = ((((x772==x773) || (('C'==x771[x772]) && (x773>=(x772+1)))) || (\exists integer x782; (((x772<x782) && (x782<=x773)) ==> ((('C'==x771[x772]) && (x782==(x772+1))) && star_starting_C(x771,x782,x773))))) || (x773>=x772));*/ /*@ predicate star_starting__orB_or_C_sCs_Bor_(char * x797, integer x798, integer x799) = (((((x798==x799) || (('B'==x797[x798]) && (x799>=(x798+1)))) || (((x798==x799) || (('C'==x797[x798]) && (x799>=(x798+1)))) || (\exists integer x811; ((((x798<=x811) && (x811<=x799)) && (('C'==x797[x798]) && (x811==(x798+1)))) && (star_starting_C(x797,x811,x799) || (\exists integer x819; ((((x811<=x819) && (x819<=x799)) && star_C(x797,x811,x819)) && ((x819==x799) || (('B'==x797[x819]) && (x799>=(x819+1))))))))))) || (\exists integer x839; (((x798<x839) && (x839<=x799)) ==> (((('B'==x797[x798]) && (x839==(x798+1))) || (\exists integer x845; ((((x798<=x845) && (x845<=x839)) && (('C'==x797[x798]) && (x845==(x798+1)))) && (\exists integer x852; ((((x845<=x852) && (x852<=x839)) && star_C(x797,x845,x852)) && (('B'==x797[x852]) && (x839==(x852+1)))))))) && star_starting__orB_or_C_sCs_Bor_(x797,x839,x799))))) || (x799>=x798));*/ /*@ predicate re0(char * x598, integer x599, integer x600) = (((x599==x600) || (('A'==x598[x599]) && (x600>=(x599+1)))) || (\exists integer x609; ((((x599<=x609) && (x609<=x600)) && (('A'==x598[x599]) && (x609==(x599+1)))) && (star_starting_A(x598,x609,x600) || (\exists integer x617; ((((x609<=x617) && (x617<=x600)) && star_A(x598,x609,x617)) && (((x617==x600) || (('B'==x598[x617]) && (x600>=(x617+1)))) || (\exists integer x630; ((((x617<=x630) && (x630<=x600)) && (('B'==x598[x617]) && (x630==(x617+1)))) && (star_starting__orB_or_C_sCs_Bor_(x598,x630,x600) || (\exists integer x638; ((((x630<=x638) && (x638<=x600)) && star__orB_or_C_sCs_Bor_(x598,x630,x638)) && (((x638==x600) || (('C'==x598[x638]) && (x600>=(x638+1)))) || (\exists integer x651; ((((x638<=x651) && (x651<=x600)) && (('C'==x598[x638]) && (x651==(x638+1)))) && (star_starting_C(x598,x651,x600) || (\exists integer x659; ((((x651<=x659) && (x659<=x600)) && star_C(x598,x651,x659)) && (((x659==x600) || (('D'==x598[x659]) && (x600>=(x659+1)))) || (\exists integer x672; ((((x659<=x672) && (x672<=x600)) && (('D'==x598[x659]) && (x672==(x659+1)))) && (star_starting_D(x598,x672,x600) || (\exists integer x680; ((((x672<=x680) && (x680<=x600)) && star_D(x598,x672,x680)) && (x600>=x680)))))))))))))))))))))))));*/ /*@ requires (((strlen(x877)>=0) && \valid(x877+(0..strlen(x877)))) && (strlen(x877)<=INT_MAX)); assigns \nothing; ensures (\result ==> re_0(x877,0,strlen(x877))); */ int dfa(char * x877) { int x879 = 1/*true*/; int x880 = 0; //@ ghost int x881 = 0; char *x882 = x877; /*@ loop invariant (((((((((strlen(x877)>=0) && \valid(x877+(0..strlen(x877)))) && ((0<=x881) && (x881<=strlen(x877)))) && (x882==(x877+x881))) && ((strlen((x877+x881))>=0) && \valid((x877+x881)+(0..strlen((x877+x881)))))) && (x879 ==> (((x880==4) ==> re_bwd_4(x877,0,x881)) && (((x880==3) ==> re_bwd_3(x877,0,x881)) && (((x880==2) ==> re_bwd_2(x877,0,x881)) && (((x880==1) ==> re_bwd_1(x877,0,x881)) && ((x880==0) ==> re_bwd_0(x877,0,x881)))))))) && (x879 ==> re0(x877,0,x881))) && ((x880==4) ==> (re_bwd_4(x877,0,x881) ==> re_0(x877,0,x881)))) && ((x880==4) || ((x880==3) || ((x880==2) || ((x880==1) || (x880==0)))))); loop assigns x882, x881, x880, x879; loop variant strlen(x882); */ for (;;) { char *x884 = x882; char x885 = x884[0]; int x886 = x885 == '\0'; int x890; if (x886) { x890 = 0/*false*/; } else { int x888 = x879; x890 = x888; } if (!x890) break; /*@assert (x879 ==> (((x880==4) ==> re_bwd_4(x877,0,x881)) && (((x880==3) ==> re_bwd_3(x877,0,x881)) && (((x880==2) ==> re_bwd_2(x877,0,x881)) && (((x880==1) ==> re_bwd_1(x877,0,x881)) && ((x880==0) ==> re_bwd_0(x877,0,x881)))))));*/ /*@assert (((x880==4) ==> re_bwd_4(x877,0,x881)) && (((x880==3) ==> re_bwd_3(x877,0,x881)) && (((x880==2) ==> re_bwd_2(x877,0,x881)) && (((x880==1) ==> re_bwd_1(x877,0,x881)) && ((x880==0) ==> re_bwd_0(x877,0,x881))))));*/ char *x942 = x882; int x944 = x880; int x945 = x944 == 4; int x1160; if (x945) { char x943 = x942[0]; int x946 = 'D' == x943; int x967; if (x946) { /*@assert re_bwd_4(x877,0,(x881+1));*/ x880 = 4; /*@assert re_bwd_4(x877,0,(x881+1));*/ /*@assert ((x880==4) ==> re_bwd_4(x877,0,(x881+1)));*/ x967 = 1/*true*/; } else { x967 = 0/*false*/; } x1160 = x967; } else { int x969 = x944 == 3; int x1158; if (x969) { char x943 = x942[0]; int x946 = 'D' == x943; int x1036; if (x946) { /*@assert re_bwd_4(x877,0,(x881+1));*/ x880 = 4; /*@assert re_bwd_4(x877,0,(x881+1));*/ /*@assert ((x880==4) ==> re_bwd_4(x877,0,(x881+1)));*/ x1036 = 1/*true*/; } else { int x990 = 'C' == x943; int x1034; if (x990) { /*@assert re_bwd_3(x877,0,(x881+1));*/ x880 = 3; /*@assert re_bwd_3(x877,0,(x881+1));*/ /*@assert ((x880==3) ==> re_bwd_3(x877,0,(x881+1)));*/ x1034 = 1/*true*/; } else { int x1011 = 'B' == x943; int x1032; if (x1011) { /*@assert re_bwd_2(x877,0,(x881+1));*/ x880 = 2; /*@assert re_bwd_2(x877,0,(x881+1));*/ /*@assert ((x880==2) ==> re_bwd_2(x877,0,(x881+1)));*/ x1032 = 1/*true*/; } else { x1032 = 0/*false*/; } x1034 = x1032; } x1036 = x1034; } x1158 = x1036; } else { int x1038 = x944 == 2; int x1156; if (x1038) { char x943 = x942[0]; int x990 = 'C' == x943; int x1081; if (x990) { /*@assert re_bwd_3(x877,0,(x881+1));*/ x880 = 3; /*@assert re_bwd_3(x877,0,(x881+1));*/ /*@assert ((x880==3) ==> re_bwd_3(x877,0,(x881+1)));*/ x1081 = 1/*true*/; } else { int x1011 = 'B' == x943; int x1079; if (x1011) { /*@assert re_bwd_2(x877,0,(x881+1));*/ x880 = 2; /*@assert re_bwd_2(x877,0,(x881+1));*/ /*@assert ((x880==2) ==> re_bwd_2(x877,0,(x881+1)));*/ x1079 = 1/*true*/; } else { x1079 = 0/*false*/; } x1081 = x1079; } x1156 = x1081; } else { int x1083 = x944 == 1; int x1154; if (x1083) { char x943 = x942[0]; int x1011 = 'B' == x943; int x1127; if (x1011) { /*@assert re_bwd_2(x877,0,(x881+1));*/ x880 = 2; /*@assert re_bwd_2(x877,0,(x881+1));*/ /*@assert ((x880==2) ==> re_bwd_2(x877,0,(x881+1)));*/ x1127 = 1/*true*/; } else { int x1104 = 'A' == x943; int x1125; if (x1104) { /*@assert re_bwd_1(x877,0,(x881+1));*/ x880 = 1; /*@assert re_bwd_1(x877,0,(x881+1));*/ /*@assert ((x880==1) ==> re_bwd_1(x877,0,(x881+1)));*/ x1125 = 1/*true*/; } else { x1125 = 0/*false*/; } x1127 = x1125; } x1154 = x1127; } else { int x1129 = x944 == 0; int x1152; if (x1129) { char x943 = x942[0]; int x1104 = 'A' == x943; int x1150; if (x1104) { /*@assert re_bwd_1(x877,0,(x881+1));*/ x880 = 1; /*@assert re_bwd_1(x877,0,(x881+1));*/ /*@assert ((x880==1) ==> re_bwd_1(x877,0,(x881+1)));*/ x1150 = 1/*true*/; } else { x1150 = 0/*false*/; } x1152 = x1150; } else { x1152 = 0/*false*/; } x1154 = x1152; } x1156 = x1154; } x1158 = x1156; } x1160 = x1158; } x879 = x1160; /*@assert (x879 ==> (((x880==4) ==> re_bwd_4(x877,0,(x881+1))) && (((x880==3) ==> re_bwd_3(x877,0,(x881+1))) && (((x880==2) ==> re_bwd_2(x877,0,(x881+1))) && (((x880==1) ==> re_bwd_1(x877,0,(x881+1))) && ((x880==0) ==> re_bwd_0(x877,0,(x881+1))))))));*/ //@ ghost int x1189 = x881; //@ ghost int x1190 = x1189 + 1; //@ ghost x881 = x1190; char *x1192 = x942+1; x882 = x1192; /*@assert (x879 ==> (((x880==4) ==> re_bwd_4(x877,0,x881)) && (((x880==3) ==> re_bwd_3(x877,0,x881)) && (((x880==2) ==> re_bwd_2(x877,0,x881)) && (((x880==1) ==> re_bwd_1(x877,0,x881)) && ((x880==0) ==> re_bwd_0(x877,0,x881)))))));*/ } int x1312 = x880; char *x1313 = x882; char x1314 = x1313[0]; int x1315 = x1314 == '\0'; int x1318; if (x1315) { int x1316 = x879; x1318 = x1316; } else { x1318 = 0/*false*/; } int x1320; if (x1318) { int x1319 = 4 == x1312; x1320 = x1319; } else { x1320 = 0/*false*/; } return x1320; }
84
/*@ axiomatic IntArray { type int_array; logic int access(int_array a, integer i); logic int_array update(int_array a, integer i, int v); axiom access_update_eq : \forall int_array a, integer i, int v; access(update(a, i, v), i) == v; axiom access_update_neq : \forall int_array a, integer i, integer j, int v; i != j ==> access(update(a, i, v), j) == access(a, j); } */ /*@ predicate Swap(int_array a1, int_array a2, integer i, integer j) = access(a1, i) == access(a2, j) && access(a1, j) == access(a2, i) && \forall integer k; k != i ==> k != j ==> access(a1, k) == access(a2, k) ; */ /*@ axiomatic Permut { predicate Permut(int_array a1, int_array a2, integer l, integer h); axiom Permut_refl: \forall int_array a; \forall integer l, integer h; Permut(a, a, l, h); axiom Permut_sym: \forall int_array a1, int_array a2, integer l, integer h; Permut(a1, a2, l, h) ==> Permut(a2, a1, l, h); axiom Permut_trans: \forall int_array a1, int_array a2, int_array a3, integer l, integer h; Permut(a1, a2, l, h) ==> Permut(a2, a3, l, h) ==> Permut(a1, a3, l, h); axiom Permut_swap: \forall int_array a1, int_array a2, integer l, integer h, integer i, integer j; l <= i <= h ==> l <= j <= h ==> Swap(a1, a2, i, j) ==> Permut(a1, a2, l, h); axiom Permut_extend: \forall int_array a1, int_array a2, integer l, integer h, integer ll, integer hh; Permut(a1, a2, l, h) ==> ll <= l ==> h <= hh ==> Permut(a1, a2, ll, hh); } */ /*@ axiomatic ArrayContents { logic int_array contents{L}(int* a) reads a[..]; axiom access_contents{L} : \forall int* a; \forall integer i; access(contents(a), i) == a[i]; } */ /*@ predicate Sorted{L}(int* a, integer l, integer h) = \forall integer i; l <= i < h ==> a[i] <= a[i+1] ; */ /*@ predicate Hnode{L}(int* a, integer i, integer h) = (2*i+1 <= h ==> a[i] >= a[2*i+1]) && (2*i+2 <= h ==> a[i] >= a[2*i+2]) ; */ /*@ predicate H{L}(int* a, integer l, integer h) = \forall integer i; l <= i <= h ==> Hnode{L}(a, i, h) ; */ //@ lemma H_init{L}: \forall int* a, integer l, integer h; l <= h < 2*l+1 ==> H{L}(a, l, h); //@ lemma H_reduce{L}: \forall int* a, integer h; 0 < h ==> H{L}(a, 0, h) ==> H{L}(a, 1, h-1); /*@ lemma H_max{L}: \forall int* a, integer h; H{L}(a, 0, h) ==> \forall integer i; 0 <= i <= h ==> a[0] >= a[i]; */ //@ lemma div2_1 : \forall int i; 0 <= i ==> 0 <= i/2 <= i; //@ lemma div2_2 : \forall int i; 0 < i ==> 0 <= i/2 < i; //@ lemma div2_3 : \forall int i; 0 <= i ==> i-1 < 2*(i/2)+1; /*@ lemma div2_4 : \forall int i, int k; 0 <= i ==> 0 <= k ==> k != (i-1)/2 ==> 2*k+1 != i; */ /*@ lemma div2_5 : \forall int i, int k; 0 <= i ==> 0 <= k ==> k != (i-1)/2 ==> 2*k+2 != i; */ /*@ requires 0 <= low <= high && \valid_range(a, low, high) && H(a, low+1, high); assigns a[low..high]; ensures Permut(contents(a), \old(update(contents(a), low, v)), low, high) && H(a, low, high); */ void sift_down(int* a, unsigned int low, unsigned int high, int v) { unsigned int i = low, child; /*@ loop invariant low <= i <= high && Permut(contents(a), \at(contents(a), Pre), low, high) && (\forall int k; low < k <= high ==> Hnode(a, k, high)) && (low < i ==> Hnode(a, low, high)) && (low <= (i-1)/2 ==> a[(i-1)/2] >= v); loop assigns a[low..high]; loop variant high - i; */ while ((child = 2*i+1) <= high) { if (child+1 <= high && a[child+1] >= a[child]) child++; if (v >= a[child]) break; a[i] = a[child]; //@ assert Hnode(a, i, high); i = child; } a[i] = v; } /*@ requires 0 <= n && \valid_range(a, 0, n-1); ensures Permut(contents(a), \old(contents(a)), 0, n-1) && Sorted(a, 0, n-1); */ void heapsort(int* a, unsigned int n) { unsigned int i; if (n <= 1) return; /*@ loop invariant 0 <= i < n && Permut(contents(a), \at(contents(a), Pre), 0, n-1) && H(a, i, n-1); loop variant i; */ for (i = n/2; i >= 1; i--) sift_down(a, i-1, n-1, a[i-1]); /*@ loop invariant 0 <= i < n && Permut(contents(a), \at(contents(a), Pre), 0, n-1) && H(a, 0, i) && Sorted(a, i+1, n-1) && \forall int k1, int k2; 0 <= k1 <= i ==> i < k2 < n ==> a[k1] <= a[k2]; loop variant i; */ for (i = n-1; i >= 1; i--) { int tmp = a[i]; a[i] = a[0]; sift_down(a, 0, i-1, tmp); } }
84
/*@ axiomatic abs { @ logic int abs(int x); @ axiom pos: \forall int x; x >= 0 ==> abs(x) == x; @ axiom neg: \forall int x; x <= 0 ==> abs(x) == -x; @ } */ /*@ ensures \result == abs(x); @ assigns \nothing; */ int abs(int x); /*@ ensures (\result == x || \result == y) @ && \result >= x && \result >= y; @ assigns \nothing; */ int max(int x, int y); /*@ ensures \result >= 0; @ assigns \nothing; */ int max_abs(int x, int y) { x = abs(x); y = abs(y); return max(x, y); }
10
#include <limits.h> /*@ predicate inv_vec_Int(int * x0, int x1) = ((x1==0) || ((x1>0) && \valid(x0+(0..x1-1))));*/ /*@ predicate inv_vec_vec_Int(int * * x16, int * x17, int x18) = (((x18==0) || ((x18>0) && (\valid(x16+(0..x18-1)) && \valid(x17+(0..x18-1))))) && (\forall int x28; (0<=x28<x18) ==> ((x17[x28]==0) || ((x17[x28]>0) && \valid(x16[x28]+(0..x17[x28]-1))))));*/ /*@ requires inv_vec_vec_Int(x66,x67,x68); assigns \nothing; ensures inv_vec_vec_Int(x66,x67,x68); */ int count_pos(int * * x66, int * x67, int x68) { int x70 = 0; /*@ loop invariant 0<=x72<=x68; loop invariant ((0<=x70) && (x70<=x72)); loop assigns x72, x70; loop variant x68-x72; */ for(int x72=0; x72 < x68; x72++) { int x75 = x70; int x81 = 0; int x74 = x67[x72]; int *x73 = x66[x72]; /*@ loop invariant 0<=x83<=x74; loop invariant ((0<=x81) && (x81<=x83)); loop assigns x83, x81; loop variant x74-x83; */ for(int x83=0; x83 < x74; x83++) { int x85 = x81; int x84 = x73[x83]; int x91 = x84 > 0; int x92; if (x91) { x92 = 1; } else { x92 = 0; } int x93 = x85 + x92; x81 = x93; } int x97 = x81; int x98 = x97 > 0; int x99; if (x98) { x99 = 1; } else { x99 = 0; } int x100 = x75 + x99; x70 = x100; } int x104 = x70; return x104; }
32
/*@ requires \valid(q) && \valid(r); requires 0<y<1000000000 && 0<=x<1000000000; assigns *q, *r ; */ void div_rem(unsigned x,unsigned y,unsigned* q,unsigned* r){ *q = x / y ; //@ assert *q==x/y; *r = x % y ; //@ assert *r==x%y; }
10
/* run.config_qualif DONTRUN: */ #define NULL ((void *) 0L) /*@ ensures e1: \result == \null; ensures e2: \result == 0; ensures e3: \result == (int *) \null; ensures e4: \result == (int *) 0; ensures e5: \result == (int *)((void *)0); */ int * f (void) { return NULL; }
7
#include <limits.h> /*@ requires x > INT_MIN; ensures 0 <= x ==> \result == x; ensures 0 > x ==> \result == -x; */ int abs_int(int x) { return (x >= 0) ? x : -x; }
5
#include <stdio.h> #include <stdlib.h> /*@ requires n >= 0; requires \valid_read(a+(0..n-1)); ensures \forall integer k; 0 <= k < n ==> a[k] == a[k]+c; */ void arrayinc(int *a,int n,int c){ /*@ loop invariant 0 <= p <= n; loop invariant \forall integer k; 0 <= k < p ==> a[k] == a[k]+c; loop invariant \forall integer k; p <= k < n ==> a[k] == a[k]; loop assigns p,a[0..(n-1)]; */ for(int p = 0;p < n;p++){ a[p] = a[p] + c; } } int main(){ int a[] = {1,2,3,4,5}; int n = 5; int c = 2; arrayinc(a,n,c); return 0; }
5
#define SPEC_INT_MIN -2147483648 #define SPEC_INT_MAX 2147483647 /*@ assigns \nothing; ensures \result >= 0; behavior positive: assumes a > 0; ensures \result == a; behavior zero: assumes a == 0; ensures \result == 0; ensures \result == a; behavior negative: assumes a < 0; ensures \result == -a; complete behaviors; disjoint behaviors; */ long spec_abs1(int a) { long abs; abs = a; if (a < 0) { abs = -abs; } return abs; } #ifdef OUT_OF_TASK #include <stdio.h> int main(void) { printf("res: %ld\n", spec_abs1(SPEC_INT_MIN + 1)); return 0; } #endif
12
#include<stdbool.h> /*@ axiomatic error_bounds { logic real ulp(real X); logic real errAdd( real X, real Y, real E_X, real E_Y) = E_X + E_Y + ulp(\abs(X + Y) + E_X + E_Y)/2; logic real errSub( real X, real Y, real E_X, real E_Y) = E_X + E_Y + ulp(\abs(X - Y) + E_X + E_Y)/2; } */ struct maybeInt { bool isValid; int value; }; /*@ assigns \nothing; ensures ! \result.isValid; */ struct maybeInt none () { struct maybeInt result = { false, 0 }; return result; } /*@ assigns \nothing; ensures \result.isValid; ensures \result.value == val; */ struct maybeInt some (int val) { struct maybeInt result = { true, val }; return result; } struct maybeFloat { bool isValid; float value; }; /*@ assigns \nothing; ensures ! \result.isValid; */ struct maybeFloat noneFloat () { struct maybeFloat result = { false, 0 }; return result; } /*@ assigns \nothing; ensures \result.isValid; ensures \result.value == val; */ struct maybeFloat someFloat (float val) { struct maybeFloat result = { true, val }; return result; } struct maybeDouble { bool isValid; double value; }; /*@ assigns \nothing; ensures ! \result.isValid; */ struct maybeDouble noneDouble () { struct maybeDouble result = { false, 0 }; return result; } /*@ assigns \nothing; ensures \result.isValid; ensures \result.value == val; */ struct maybeDouble someDouble (double val) { struct maybeDouble result = { true, val }; return result; } struct maybeBool { bool isValid; double value; }; /*@ assigns \nothing; ensures ! \result.isValid; */ struct maybeBool noneBool () { struct maybeBool result = { false, false }; return result; } /*@ assigns \nothing; ensures \result.isValid; ensures \result.value == val; */ struct maybeBool someBool (bool val) { struct maybeBool result = { true, val }; return result; }
36
/*@ ensures \result <= sizeof(int); */ int f() { return sizeof(char); }
3
/* * memswap() * * Swaps the contents of two nonoverlapping memory areas. * This really could be done faster... */ #include <string.h> /*@ requires n >= 0; requires \valid(((char*)m1)+(0..n-1)); requires \valid(((char*)m2)+(0..n-1)); requires \separated(((char*)m1)+(0..n-1), ((char*)m2)+(0..n-1)); assigns ((char*)m1)[0..n-1]; assigns ((char*)m2)[0..n-1]; ensures \forall integer i; 0 <= i < n ==> ((char*)m1)[i] == \old(((char*)m2)[i]); ensures \forall integer i; 0 <= i < n ==> ((char*)m2)[i] == \old(((char*)m1)[i]); @*/ void memswap(void *m1, void *m2, size_t n) { char *p = m1; char *q = m2; char tmp; /*@ loop invariant \base_addr(p) == \base_addr(m1); loop invariant \base_addr(q) == \base_addr(m2); loop invariant 0 <= n <= \at(n, Pre); loop invariant p == m1+(\at(n, Pre) - n); loop invariant q == m2+(\at(n, Pre) - n); loop invariant \forall integer i; 0 <= i < (\at(n, Pre) - n) ==> ((char*)m2)[i] == \at(((char*)m1)[i], Pre); loop invariant \forall integer i; 0 <= i < (\at(n, Pre) - n) ==> ((char*)m1)[i] == \at(((char*)m2)[i], Pre); loop invariant \forall integer i; (\at(n, Pre) - n) <= i < \at(n, Pre) ==> ((char*)m1)[i] == \at(((char*)m1)[i], Pre); loop invariant \forall integer i; (\at(n, Pre) - n) <= i < \at(n, Pre) ==> ((char*)m2)[i] == \at(((char*)m2)[i], Pre); loop assigns n, tmp, ((char*)m1)[0..(\at(n, Pre) - n - 1)], ((char*)m2)[0..(\at(n, Pre) - n - 1)], p, q; loop variant n; @*/ while (/*n--*/ n) { tmp = *p; *p = *q; *q = tmp; p++; q++; n--; // inserted code } }
33
/* run.config COMMENT: bts #1478 about wrong detection of initializers in pre-analysis */ int global_i; int* global_i_ptr = &global_i; int global_i = 0; /*@ requires global_i == 0; requires \valid(global_i_ptr); requires global_i_ptr == &global_i; */ void loop(void) { } int main(void) { loop(); return 0; }
7
/*@ requires \valid(p+ (0..1)); ensures p[0] == \old(p[1]); ensures p[1] == \old(p[0]); assigns p[0], p[1]; */ void array_swap(int* p) { int tmp = p[0]; p[0] = p[1]; p[1] = tmp; }
10
// Returns the index of an element in a given array /*@ requires n>0; requires \valid(t+(0..n-1)); behavior success: assumes \exists integer i; 0<=i<n && t[i] == e; ensures 0 <= \result < n && t[\result]==e; behavior failure: assumes \forall integer i; 0<=i<n ==> t[i]!=e; ensures \result==-1; */ int index(int t[],int n,int e) { /*@ loop invariant 0<=i<=n; loop invariant \forall integer j; 0<=j<i ==> t[j] == e; loop variant n-i; */ for(int i=0;i<n;i++) { if( t[i] == e ) return i; } return -1; }
10
#define SPEC_INT_MIN -2147483648 #define SPEC_INT_MAX 2147483647 /*@ //requires SPEC_INT_MIN < a <= SPEC_INT_MAX; requires SPEC_INT_MIN < a; assigns \nothing; ensures \result >= 0; behavior positive: assumes a > 0; ensures \result == a; behavior zero: assumes a == 0; ensures \result == 0; ensures \result == a; behavior negative: assumes a < 0; ensures \result == -a; complete behaviors; disjoint behaviors; */ int spec_abs2(int a) { int abs; if (a < 0) { abs = -a; } else { abs = a; } return abs; } #ifdef OUT_OF_TASK #include <stdio.h> int main(void) { printf("res: %d\n", spec_abs2(SPEC_INT_MIN + 1)); return 0; } #endif
12
/* Run with: * * frama-c -wp -wp-rte -wp-prover alt-ergo -wp-timeout 10 -wp-verbose 0 \ * kylikeio.c -then -report * * Tested with Frama-C Aluminium-20160502. */ /*@ predicate canSee{L}(integer N, int *x, integer i) = @ \forall integer j; i < j < N ==> \at(x[i], L) > \at(x[j], L); @*/ /*@ predicate countRangeFrom{L}(integer N, int *x, integer i, integer c) = @ i >= N ? c == 0 : @ canSee{L}(N, x, i) ? countRangeFrom{L}(N, x, i+1, c-1) @ : countRangeFrom{L}(N, x, i+1, c); @*/ /*@ requires N > 0; @ requires \valid(a + (0..N-1)); @ ensures countRangeFrom(N, a, 0, \result); @*/ int count(int N, int* a) { int max = a[N-1]; int result = 1; /*@ loop invariant -1 <= i <= N-2; @ loop invariant result + i <= N-1; @ loop invariant \exists integer j; i < j < N && a[j] == max; @ loop invariant \forall integer j; i < j < N ==> a[j] <= max; @ loop invariant countRangeFrom(N, a, i+1, result); @ loop assigns i, max, result; @ loop variant i+1; @*/ for (int i = N-2; i >= 0; --i) if (a[i] > max) { max = a[i]; ++result; } return result; }
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#include <limits.h> /*@ requires x > INT_MIN; assigns \nothing; behavior positive: assumes x >= 0; ensures \result == x; behavior negative: assumes x < 0; ensures \result == -x; complete behaviors; disjoint behaviors; */ int abs(int x) { if (x < 0) return -x; else if(x >= 0) return x; }
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/* * @UBERXMHF_LICENSE_HEADER_START@ * * uber eXtensible Micro-Hypervisor Framework (Raspberry Pi) * * Copyright 2018 Carnegie Mellon University. All Rights Reserved. * * NO WARRANTY. THIS CARNEGIE MELLON UNIVERSITY AND SOFTWARE ENGINEERING * INSTITUTE MATERIAL IS FURNISHED ON AN "AS-IS" BASIS. CARNEGIE MELLON * UNIVERSITY MAKES NO WARRANTIES OF ANY KIND, EITHER EXPRESSED OR IMPLIED, * AS TO ANY MATTER INCLUDING, BUT NOT LIMITED TO, WARRANTY OF FITNESS FOR * PURPOSE OR MERCHANTABILITY, EXCLUSIVITY, OR RESULTS OBTAINED FROM USE OF * THE MATERIAL. CARNEGIE MELLON UNIVERSITY DOES NOT MAKE ANY WARRANTY OF * ANY KIND WITH RESPECT TO FREEDOM FROM PATENT, TRADEMARK, OR COPYRIGHT * INFRINGEMENT. * * Released under a BSD (SEI)-style license, please see LICENSE or * contact [email protected] for full terms. * * [DISTRIBUTION STATEMENT A] This material has been approved for public * release and unlimited distribution. Please see Copyright notice for * non-US Government use and distribution. * * Carnegie Mellon is registered in the U.S. Patent and Trademark Office by * Carnegie Mellon University. * * @UBERXMHF_LICENSE_HEADER_END@ */ /* * Author: Amit Vasudevan ([email protected]) * */ #include <stdint.h> #include <string.h> /* u32 strnlen(const char * s, u32 count){ const char *sc; for (sc = s; count-- && *sc != '\0'; ++sc); return (u32)(sc - s); }*/ /*@ requires maxlen >= 0; requires \valid(s+(0..maxlen-1)); assigns \nothing; behavior bigger: assumes \forall integer i; 0 <= i < maxlen ==> s[i] != 0; ensures \result == maxlen; behavior smaller: assumes \exists integer i; 0 <= i < maxlen && s[i] == 0; ensures \result <= maxlen; complete behaviors; disjoint behaviors; */ size_t strnlen(const char *s, size_t maxlen) { const char *ss = s; /* Important: the maxlen test must precede the reference through ss; since the byte beyond the maximum may segfault */ /*@ loop invariant 0 <= maxlen <= \at(maxlen,Pre); loop invariant \forall integer i; 0 <= i < (\at(maxlen, Pre) - maxlen) ==> s[i] != 0; loop invariant ss == s+(\at(maxlen, Pre) - maxlen); loop invariant s <= ss <= s+\at(maxlen, Pre); loop assigns maxlen, ss; loop variant maxlen; */ while ((maxlen > 0) && *ss) { ss++; maxlen--; } return ss - s; }
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#include <limits.h> #include <string.h> /*@ requires (((strlen(x0)>=0) && \valid(x0+(0..strlen(x0)))) && (strlen(x0)<=INT_MAX)); assigns \nothing; */ int dfa(char * x0) { int x2 = 1/*true*/; int x3 = 0; //@ ghost int x4 = 0; char *x5 = x0; /*@ loop invariant (((((strlen(x0)>=0) && \valid(x0+(0..strlen(x0)))) && ((0<=x4) && (x4<=strlen(x0)))) && (x5==(x0+x4))) && ((strlen((x0+x4))>=0) && \valid((x0+x4)+(0..strlen((x0+x4)))))); loop invariant ((x5[0]=='\0') ==> (strlen(x0)==x4)); loop invariant ((!(x5[0]=='\0')) ==> (strlen(x0)!=x4)); loop invariant ((x3==4) || ((x3==3) || ((x3==2) || ((x3==1) || (x3==0))))); loop assigns x5, x4, x3, x2; loop variant strlen(x5); */ for (;;) { char *x7 = x5; char x8 = x7[0]; int x9 = x8 == '\0'; int x13; if (x9) { x13 = 0/*false*/; } else { int x11 = x2; x13 = x11; } if (!x13) break; char *x41 = x5; char *x42 = x41+1; x5 = x42; /*@ghost x4 = (x4+1);*/ } char *x88 = x5; char x89 = x88[0]; int x90 = x89 == '\0'; int x93; if (x90) { int x91 = x2; x93 = x91; } else { x93 = 0/*false*/; } int x97; if (x93) { int x94 = x3; int x95 = x94 == 4; x97 = x95; } else { x97 = 0/*false*/; } /*@assert ((x5[0]=='\0') || (!x2));*/ return x97; }
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#include <limits.h> /*@ predicate inv_vec_Int(int * x0, int x1) = ((x1==0) || ((x1>0) && \valid(x0+(0..x1-1))));*/ /*@ requires inv_vec_Int(x16,x17); assigns \nothing; ensures inv_vec_Int(x16,x17); */ int count_pos(int * x16, int x17) { int x19 = 0; /*@ loop invariant 0<=x21<=x17; loop invariant ((0<=x19) && (x19<=x21)); loop assigns x21, x19; loop variant x17-x21; */ for(int x21=0; x21 < x17; x21++) { int x23 = x19; int x22 = x16[x21]; int x29 = x22 > 0; int x30; if (x29) { x30 = 1; } else { x30 = 0; } int x31 = x23 + x30; x19 = x31; } int x35 = x19; return x35; }
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/*@ requires \valid(p); assigns \nothing; ensures \result == 42; */ int foo(int* p) { return 42; }
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/*@ predicate sorted(int *t,integer i,integer j) = @ \forall integer k, integer l; i <= k < l <= j ==> t[k] <= t[l]; @*/ /*@ requires N>=1 && \valid(A+(0..N-1)); @ assigns A[0..N-1]; @ ensures sorted(A,0,N-1); @*/ void insertionSort(int A[], int N) { int i, j, key; /*@ loop assigns i, key, j, A[0..i-1]; @ loop invariant 1<=i<=N && sorted(A,0,i); @ loop variant N-i; @*/ for (i=1 ; i<N ; i++) { key = A[i]; j = i; /*@ loop assigns j, A[0..i]; @ loop invariant 0 <= j <= i; @ loop invariant j == i ==> sorted(A,0,i); @ loop invariant j < i ==> sorted(A,0,i+1); @ loop invariant \forall integer k; j+1 <= k <= i ==> key < A[k]; @ loop variant j; @*/ while (j>0 && A[j-1] > key) { A[j] = A[j-1]; j--; } A[j] = key; } } /* let insertion_sort (a: array int) = ensures { sorted a } for i = 1 to length a - 1 do invariant { sorted_sub a 0 i } let v = a[i] in let j = ref i in while !j > 0 && a[!j - 1] > v do invariant { 0 <= !j <= i } invariant { !j = i -> sorted_sub a 0 i } invariant { !j < i -> sorted_sub a 0 (i+1) } invariant { forall k: int. !j+1 <= k <= i -> v < a[k] } variant { !j } a[!j] <- a[!j - 1]; j := !j - 1 done; a[!j] <- v done */
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struct counter { int seconds, minutes, hours; }; struct counter c; /*@ requires 0<=c.seconds<60 && 0<=c.minutes<60 && 0<=c.hours<24; behavior one: assumes c.seconds < 59 && c.minutes < 59; ensures c.seconds == \old(c.seconds)+1; behavior two: assumes c.seconds == 59 && c.minutes < 59; ensures c.seconds == 0; ensures c.minutes == \old(c.minutes)+1; behavior three: assumes c.seconds < 59 && c.minutes == 59; ensures c.seconds == \old(c.seconds)+1; behavior four: assumes c.seconds == 59 && c.minutes == 59 && c.hours < 23 ; ensures c.seconds == 0; ensures c.minutes == 0; ensures c.hours == \old(c.hours)+1; behavior five: assumes c.seconds == 59 && c.minutes == 59 && c.hours == 23 ; ensures c.seconds == 0; ensures c.minutes == 0; ensures c.hours == 0; complete behaviors; disjoint behaviors; */ void tick() { if (c.seconds < 59) c.seconds++; else { c.seconds = (c.seconds + 1) % 60; if (c.minutes < 59) c.minutes++; else c.minutes = (c.minutes + 1) % 60; if (c.hours < 23) c.hours++; else c.hours = 0; } }
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/*@ requires n >= 0; requires \valid(t+(0..(n-1))); behavior empty : assumes n==0; ensures \result==0; behavior not_empty: assumes n>0; ensures 0 <= \result < n; ensures \forall integer k; 0 <= k < n ==> t[k] >= t[\result]; ensures \forall integer k; 0 <= k < \result ==> t[k] > t[\result]; complete behaviors empty, not_empty; disjoint behaviors empty, not_empty; */ int min(int * t, int n) { if (n==0) { return 0; } else { int maxInd = 0; int i =0; /*@ loop assigns i, maxInd; loop invariant 0 <= i <= n; loop invariant 0 <= maxInd < n; loop invariant 0 <= maxInd <= i; loop invariant \forall integer k; 0 <= k < i ==> t[k] >= t[maxInd]; loop invariant \forall integer k; 0 <= k < maxInd ==> t[k] > t[maxInd]; loop variant n-i; */ for(i=0;i<n;i++) { if (t[i] < t[maxInd]) { maxInd = i; } } return maxInd; } }
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#include <string.h> /*@ logic integer cypher(integer s) = s==26 ? 0 : s+1; logic integer decypher(integer s) = s==0 ? 26 : s-1; */ /*@ requires 0 <= s <= 26; ensures 0 <= \result <= 26; ensures \result == cypher(s); assigns \nothing; */ int cypher(int s) { return s==26 ? 0 : s+1; } /*@ requires 0 <= s <= 26; ensures 0 <= \result <= 26; ensures \result == decypher(s); assigns \nothing; */ int decypher(int s) { return s==0 ? 26 : s-1; } /*@ requires n > 0; requires \valid(s1+(0..n-1)); requires \valid(s2+(0..n-1)); requires \valid(s3+(0..n-1)); requires \forall int i1,i2,i3; 0 <= i1 < n && 0 <= i2 < n && 0 <= i3 < n ==> \separated(s1+i1,s2+i2,s3+i3); requires \forall int i; 0 <= i < n ==> 0 <= s1[i] <= 26; ensures \forall int i; 0 <= i < n ==> s2[i]==cypher(s1[i]); ensures \forall int i; 0 <= i < n ==> 0 <= s2[i] <= 26; ensures \forall int i; 0 <= i < n ==> \old(s1[i])==s1[i]; ensures \forall int i; 0 <= i < n ==> \old(s3[i])==s3[i]; assigns s2[0..n-1]; */ void encode(int* s1, int* s2, int* s3, int n) { /*@ loop invariant 0 <= i <= n; loop invariant \forall int j; 0 <= j < n ==> 0 <= s1[j] <= 26; loop invariant \forall int i; 0 <= i < n ==> \at(s1[i],Pre)==s1[i]; loop invariant \forall int i; 0 <= i < n ==> \at(s3[i],Pre)==s3[i]; loop invariant \forall int j; 0 <= j < i ==> s2[j]==cypher(s1[j]); loop assigns i, s2[0..n-1]; loop variant n - i; */ for (int i=0; i<n; i++) { s2[i] = cypher(s1[i]); } } /*@ requires n > 0; requires \valid(s1+(0..n-1)); requires \valid(s2+(0..n-1)); requires \valid(s3+(0..n-1)); requires \forall int i1,i2,i3; 0 <= i1 < n && 0 <= i2 < n && 0 <= i3 < n ==> \separated(s1+i1,s2+i2,s3+i3); requires \forall int i; 0 <= i < n ==> 0 <= s1[i] <= 26; ensures \forall int i; 0 <= i < n ==> s2[i]==decypher(s1[i]); ensures \forall int i; 0 <= i < n ==> 0 <= s2[i] <= 26; ensures \forall int i; 0 <= i < n ==> \old(s1[i])==s1[i]; ensures \forall int i; 0 <= i < n ==> \old(s3[i])==s3[i]; assigns s2[0..n-1]; */ void decode(int* s1, int* s2, int* s3, int n) { /*@ loop invariant 0 <= i <= n; loop invariant \forall int j; 0 <= j < n ==> 0 <= s1[j] <= 26; loop invariant \forall int i; 0 <= i < n ==> \at(s1[i],Pre)==s1[i]; loop invariant \forall int i; 0 <= i < n ==> \at(s3[i],Pre)==s3[i]; loop invariant \forall int j; 0 <= j < i ==> s2[j]==decypher(s1[j]); loop assigns i, s2[0..n-1]; loop variant n - i; */ for (int i=0; i<n; i++) { s2[i] = decypher(s1[i]); } } /*@ requires n > 0; requires \valid(s1+(0..n-1)); requires \valid(s2+(0..n-1)); requires \valid(s3+(0..n-1)); requires \forall int i1,i2,i3; 0 <= i1 < n && 0 <= i2 < n && 0 <= i3 < n ==> \separated(s1+i1,s2+i2,s3+i3); requires \forall int i; 0 <= i < n ==> 0 <= s1[i] <= 26; ensures \forall int i; 0 <= i < n ==> s3[i]==s1[i]; ensures \forall int i; 0 <= i < n ==> \old(s1[i])==s1[i]; assigns s2[0..n-1], s3[0..n-1]; */ void autoencode(int* s1, int* s2, int* s3, int n) { encode(s1, s2, s3, n); decode(s2, s3, s1, n); //@assert \forall int i; 0 <= i < n ==> \at(s1[i],Pre)==s1[i]; //@assert \forall int i; 0 <= i < n ==> s2[i]==cypher(s1[i]); //@assert \forall int i; 0 <= i < n ==> s3[i]==decypher(s2[i]); //@assert \forall int i; 0 <= i < n ==> s3[i]==decypher(cypher(s1[i])); //@assert \forall int i; 0 <= i < n ==> s3[i]==s1[i]; }
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/*@ predicate Swap{L1,L2}(int *a, integer i, integer j) = @ \at(a[i],L1) == \at(a[j],L2) && @ \at(a[j],L1) == \at(a[i],L2) && @ \forall integer k; k != i && k != j @ ==> \at(a[k],L1) == \at(a[k],L2); @*/ /*@ predicate sorted(int *t,integer i,integer j) = @ \forall integer k, integer l; i <= k < l <= j ==> t[k] <= t[l]; @*/ /*@ requires N>=1 && \valid(A+(0..N-1)); @ assigns A[0..N-1]; @ ensures sorted(A,0,N-1); @*/ void selectionSort(int A[], int N) { int i, j, min, temp; /*@ loop assigns i,j,min,temp, A[0..N-1]; @ loop invariant 0<=i<=N-1 && sorted(A,0,i) && (\forall integer k1, integer k2; (0<=k1<i<k2<N)==>A[k1]<=A[k2]); @ loop variant N-i; @*/ for (i = 0; i < N-1; i++) { min = i; /*@ loop assigns j,min; @ loop invariant i+1<=j<=N && i<=min<j && (\forall integer k; (i<=k<j)==>A[min]<=A[k]); @ loop variant N-j; @*/ for (j = i+1; j < N; j++){ if (A[j] < A[min]){ min = j; } } if(min!=i){ temp = A[i]; A[i] = A[min]; A[min] = temp; } } }
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/*@ ensures \result == *p; */ int foo(int* p) { return *p; }
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/* * strnlen() */ #include <string.h> /*@ requires maxlen >= 0; requires \valid(s+(0..maxlen-1)); assigns \nothing; behavior bigger: assumes \forall integer i; 0 <= i < maxlen ==> s[i] != 0; ensures \result == maxlen; behavior smaller: assumes \exists integer i; 0 <= i < maxlen && s[i] == 0; ensures \result <= maxlen; complete behaviors; disjoint behaviors; */ size_t strnlen(const char *s, size_t maxlen) { const char *ss = s; /* Important: the maxlen test must precede the reference through ss; since the byte beyond the maximum may segfault */ /*@ loop invariant 0 <= maxlen <= \at(maxlen,Pre); loop invariant \forall integer i; 0 <= i < (\at(maxlen, Pre) - maxlen) ==> s[i] != 0; loop invariant ss == s+(\at(maxlen, Pre) - maxlen); loop invariant s <= ss <= s+\at(maxlen, Pre); loop assigns maxlen, ss; loop variant maxlen; */ while ((maxlen > 0) && *ss) { ss++; maxlen--; } return ss - s; }
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/*@ requires a_valid: \valid(a); requires b_valid: \valid(b); ensures a_value: *a == \at(*b, Pre); ensures b_value: *b == \at(*a, Pre); */ void swap(int* a, int* b) { int tmp = *a; *a = *b; *b = tmp; }
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/*@ requires y > 10; @ ensures \result >= 0; */ int g(int y){ int x=0; if(y>0){ x=100; x=x+50; x=x-100; }else{ x = x - 150; x=x-100; x=x+100; } return x; } int main(){ int a = g(11); return a; }
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/* run.config COMMENT: function call STDOPT: +"-val-builtin malloc:Frama_C_alloc_size,free:Frama_C_free -no-val-malloc-returns-null" */ #include <stdlib.h> //extern void *malloc(unsigned int size); /*@ ensures \valid(\result); */ int *f(int *x, int *y) { *y = 1; return x; } int main() { int x = 0, *p, *q = malloc(sizeof(int)), *r = malloc(sizeof(int)); p = f(&x, q); q = f(&x, r); return 0; }
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typedef struct _list { int i; } *list; /*@ requires \valid(p); */ void f(list p) {} /*@ requires \valid(p); */ void g(struct _list* p) {}
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#ifndef SPEC_SORTING_H #define SPEC_SORTING_H /*@ predicate Swap{L1,L2}(int *a, integer i, integer j) = \at(a[i],L1) == \at(a[j],L2) && \at(a[j],L1) == \at(a[i],L2) && \forall integer k; k != i && k != j ==> \at(a[k],L1) == \at(a[k],L2); */ /*@ inductive Permut{L1,L2}(int *a, integer l, integer h) { case Permut_refl{L}: \forall int *a, integer l, h; Permut{L,L}(a, l, h); case Permut_sym{L1,L2}: \forall int *a, integer l, h; Permut{L1,L2}(a, l, h) ==> Permut{L2,L1}(a, l, h); case Permut_trans{L1,L2,L3}: \forall int *a, integer l, h; Permut{L1,L2}(a, l, h) && Permut{L2,L3}(a, l, h) ==> Permut{L1,L3}(a, l, h); case Permut_swap{L1,L2}: \forall int *a, integer l, h, i, j; l <= i <= h && l <= j <= h && Swap{L1,L2}(a, i, j) ==> Permut{L1,L2}(a, l, h); } */ /*@ predicate Sorted{L}(int *a, integer l, integer h) = \forall integer i,j; l <= i <= j < h ==> a[i] <= a[j]; */ /*@ requires \valid(t+i); requires \valid(t+j); assigns t[i],t[j]; ensures Swap{Old,Here}(t,i,j); */ void sort_swap(int t[], int i, int j) { int tmp = t[i]; t[i] = t[j]; t[j] = tmp; } #endif
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/*@ requires \valid(a) && \valid(b); ensures A: *a==\old(*b); ensures B: *b==\old(*a); assigns *a, *b; */ void swap(int *a, int *b) { int temp = *a; *a = *b; *b = temp; }
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#define N 12 int array[ N ]; /*@ ensures 0 <= \result < N; */ int get_index(void); void main() { int i = get_index(); array[ i ] = 3; } #ifndef FRAMA_C int get_index(void) { int i = 7; return i; } #endif
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/*@ requires \valid(p) && \valid(q); ensures \result >= *p && \result >= *q; ensures \result == *p || \result == *q; */ int max_ptr ( int *p, int *q ) { *p = 0; *q = 0; return 0 ; }
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struct account { int lower_limit; int balance; int upper_limit; }; /*@ predicate valid_account{L}(struct account* account) = \valid(account) && account->lower_limit <= account->balance <= account->upper_limit; */ /*@ requires valid_account(account) && 0<= amount <= account->upper_limit - account -> balance; assigns account->balance; ensures valid_account(account) && account->balance == \at(account->balance,Pre) + amount; */ void deposit(struct account* account, int amount) { account->balance += amount; } /*@ requires valid_account(account) && 0<= amount <= account -> balance -account->lower_limit; assigns account->balance; ensures valid_account(account) && account->balance == \at(account->balance,Pre) - amount; */ void withdraw(struct account* account, int amount) { account->balance -= amount; } /*@ requires valid_account(account); assigns \nothing; ensures \result == account -> balance; */ int get_balance(struct account* account) { return account ->balance; } /*@ requires \valid(account) && lower_limit <= 0 <= upper_limit; assigns account->balance, account->lower_limit, account->upper_limit; ensures valid_account(account) && account->balance == 0 && account->lower_limit == lower_limit && account->upper_limit == upper_limit; */ void init_account(struct account* account, int lower_limit, int upper_limit) { account->lower_limit = lower_limit; account -> upper_limit = upper_limit; account->balance = 0; } int main () { struct account _Account; struct account* myAccount = &_Account; init_account(myAccount,-100,200); deposit(myAccount,10); withdraw(myAccount,20); int current_balance = get_balance(myAccount); //@ assert current_balance == -10; return 0; }
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/*@ requires \valid(a + (0..n-1)); requires \forall integer i, integer j; 0 <= i < j < n ==> a[i] <= a[j]; assigns \nothing; ensures 0 <= \result <= n; ensures \forall integer k; 0 <= k < \result ==> a[k] < val; ensures \forall integer k; \result <= k < n ==> val <= a[k]; */ unsigned lower_bound(const int *a, unsigned n, int val) { unsigned left = 0; unsigned right = n; unsigned middle = 0; /*@ loop invariant 0 <= left <= right <= n; loop assigns middle, left, right; loop invariant \forall integer i; 0 <= i < left ==> a[i] < val; loop invariant \forall integer i; right <= i < n ==> val <= a[i]; loop variant right - left; */ while (left < right) { middle = left + (right - left) / 2; if (a[middle] < val) { //@ assert \forall integer i; 0 <= i < middle+1 ==> a[i] < val; left = middle + 1; } else right = middle; } return left; } /*@ requires \valid(a + (0..n-1)); requires \forall integer i, integer j; 0 <= i < j < n ==> a[i] <= a[j]; assigns \nothing; ensures 0 <= \result <= n; ensures \forall integer k; 0 <= k < \result ==> a[k] < val; ensures \forall integer k; \result <= k < n ==> val <= a[k]; */ unsigned lower_bound_raw(const int *a, unsigned n, int val) { unsigned i = 0; /*@ loop invariant 0 <= i <= n; loop invariant \forall integer j; 0 <= j < i ==> a[j] < val; loop invariant \forall integer j; i <= j < n ==> a[j] >= a[i]; loop assigns i; loop variant n - i; */ for(; i < n; ++i) { if (a[i] >= val) { break; } } return i; } #ifdef OUT_OF_TASK #include <stdio.h> #define ARRAY_SIZE(array) (sizeof(array)/sizeof((array)[0])) int main(void) { int a[] = {0}; int b[] = {0,1}; int c[] = {0,1,2,3,4,5}; int res; res = lower_bound(a, ARRAY_SIZE(a), 0); printf("res: %d\n", res); res = lower_bound(b, ARRAY_SIZE(b), 1); printf("res: %d\n", res); res = lower_bound(c, ARRAY_SIZE(c), 10); printf("res: %d\n", res); } #endif
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/*@ predicate all_equal_in_range{L}(int *x, integer minidx, integer maxidx) = @ \forall integer k; minidx <= k < minidx + maxidx ==> \at(x[minidx], L) == \at(x[k], L) @ ; */ /*@ predicate not_equal_in_range{L}(int *x, integer minidx, integer maxidx) = @ \exists integer k; minidx <= k < maxidx && \at(x[minidx], L) != \at(x[k], L); */ /*@ predicate best_is_not_best{L}(int *x, integer maxIdx, integer best) = @ \forall integer k1; 0 <= k1 < maxIdx - best - 1 ==> all_equal_in_range{L}(x, k1, k1 + best) && (\at(x[k1], L) == \at(x[k1 + best + 1], L)); */ /*@ predicate best_is_best{L}(int *x, integer i, integer N, integer best) = @ \forall integer k1; (0 <= k1 < i ) ==> @ (\forall integer j; (0 < j <= N && j + k1 <= N) && all_equal_in_range{L}(x, k1, j) ==> j <= best); @*/ /*@ predicate all_smaller_than_best{L}(int *x, integer i, integer maxidx, integer best) = @ \forall integer k1; (i<= k1 < maxidx && k1 + best < maxidx && (0 < k1 < maxidx ==> \at(x[k1],L) != \at(x[k1-1],L)) && all_equal_in_range{L}(x, k1, best) ) @ ==> \at(x[k1],L) != \at(x[k1+best],L); @ @*/ /*@ requires N >= 1; @ requires N <= 1000000; @ requires \valid(x + (0..N-1)); @ ensures \exists integer k1; 0 <= k1 < N && all_equal_in_range(x, k1, \result); @ ensures best_is_best(x, N, N, \result); @ ensures \forall integer k1; (0 <= k1 < N && k1 + \result < N && all_equal_in_range(x, k1, \result)) ==> x[k1] != x[k1+\result]; @ ensures \forall integer k1; (0 <= k1 < N ==> !all_equal_in_range(x, k1, \result + 1)); @ ensures !(\exists integer k1; 0 <= k1 < N && k1 + \result < N && all_equal_in_range(x, k1, \result) && x[k1] == x[k1+\result]); @ ensures !(\exists integer k1; 0 <= k1 < N && k1 + \result < N && all_equal_in_range(x, k1, \result+1) ); @ ensures all_smaller_than_best(x, 0, N, \result); */ int countSameConsecutive(int N, int x[]) { int best = 0, i = 0; /*@ assert i < N; */ /*@ loop invariant 0 <= i <= N; @ loop invariant i == 0 ==> best == 0; @ loop invariant i > 0 ==> 1 <= best <= N; @ loop invariant i > 0 ==> \exists integer k1; 0 <= k1 < i && all_equal_in_range(x, k1, best); @ loop invariant 0 < i < N ==> x[i] != x[i-1]; @ loop invariant i > 0 ==> all_smaller_than_best(x, 0, i, best); @ loop assigns i, best; @ loop variant N - i; */ while (i < N) { int j = i+1; /*@ loop invariant i < j <= N; @ loop invariant all_equal_in_range(x, i, j-i); @ loop assigns j; @ loop variant N - j; */ while (j < N && x[j] == x[i]) ++j; /*@ assert (j == N) || (x[j] != x[j-1] && !all_equal_in_range(x, i, j + 1) && x[j] != x[i]); */ /*@ assert i == 0 && j == N ==> all_equal_in_range(x, 0, N);*/ if (j-i > best) best = j-i; /*@ assert \forall integer k; (i <= k <= j) ==> best >= k - i; */ /*@ assert best >= j - i >= 1; */ i = j; } /*@ assert best <= N; */ return best; }
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/*@ predicate is_divisor(integer m, integer n) = (m != 0) ==> n % m == 0; */ /*@ predicate is_gcd(integer z, integer x1, integer x2) = is_divisor(z, x1) && is_divisor(z, x2) && \forall integer i; is_divisor(i, x1) && is_divisor(i, x2) ==> (i <= z); */ /*@ axiomatic gcd { logic integer gcd(integer a, integer b); axiom nil: \forall integer n; gcd(n,0) == n; axiom next: \forall integer a, b; gcd(b, a % b) == gcd(a,b); lemma gcd_def: \forall integer a, b; is_gcd(gcd(a, b), a, b); } */ /*@ requires x1 > 0 && x2 > 0; assigns \nothing; ensures is_gcd(\result, x1, x2); */ unsigned gcd(unsigned x1, unsigned x2) { unsigned y1 = x1; unsigned y2 = x2; unsigned tmp = 0; if (y1 > y2) { y1 = x2; y2 = x1; } //@ assert y1 == \min(x1, x2); //@ assert y2 == \max(x1, x2); /*@ loop invariant 0 <= y1 <= y2; loop invariant y2 > 0; loop invariant (y1 > 0) ==> gcd(x1, x2) == gcd(y1, y2); loop invariant (y1 == 0) ==> gcd(x1, x2) == y2; loop variant y1; */ while (y1 != 0) { tmp = y1; y1 = y2 % y1; y2 = tmp; } return y2; } /*@ requires x1 > 0; decreases x2; assigns \nothing; ensures is_gcd(\result, x1, x2); ensures \result == gcd(x1, x2); */ unsigned gcd_rec(unsigned x1, unsigned x2) { if (x2 == 0) return x1; return gcd_rec(x2, x1 % x2); } /*@ requires x1 > 0 && x2 > 0; assigns \nothing; ensures is_gcd(\result, x1, x2); */ unsigned gcd_raw(unsigned x1, unsigned x2) { unsigned min = x1 > x2 ? x2 : x1; //@ assert min == \min(x1, x2); unsigned gcd = 1; /*@ loop invariant 2 <= i <= min + 1; loop invariant 1 <= gcd < i; loop invariant is_divisor(gcd, x1); loop invariant is_divisor(gcd, x2); loop invariant \forall integer j; 0 <= j < i && is_divisor(j, x1) && is_divisor(j, x2) ==> (j <= gcd); loop invariant gcd <= gcd(x1, x2); loop assigns gcd; loop variant min - i; */ for(unsigned i = 2; i <= min; ++i) { if (x1 % i == 0 && x2 % i == 0) { gcd = i; } } return gcd; } #ifdef OUT_OF_TASK #include <stdio.h> int main(int argc, char **argv) { for(int i = 1; i < 1000; ++i) { for(int j = 1; j < 1000; ++j) { int res1 = gcd(i, j); int res2 = gcd_rec(i, j); int res3 = gcd_raw(i, j); if (res1 != res2 || res2 != res3) { printf("i: %d, j: %d, res1: %d, res2: %d, res3: %d\n", i, j, res1, res2, res3); } } } return 0; } #endif
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#include <limits.h> #include <string.h> /*@ predicate match_w(char * x0) = ((x0[0]=='a') && ((x0[1]=='a') && ((x0[2]=='b') && ((x0[3]=='a') && (x0[4]=='a')))));*/ /*@ assigns \nothing; ensures \result <==> match_w(x0); */ int match_w(char * x0) { char x2 = x0[0]; int x3 = x2 == 'a'; int x16; if (x3) { char x4 = x0[1]; int x5 = x4 == 'a'; int x15; if (x5) { char x6 = x0[2]; int x7 = x6 == 'b'; int x14; if (x7) { char x8 = x0[3]; int x9 = x8 == 'a'; int x13; if (x9) { char x10 = x0[4]; int x11 = x10 == 'a'; int x12; if (x11) { x12 = 1/*true*/; } else { x12 = 0/*false*/; } x13 = x12; } else { x13 = 0/*false*/; } x14 = x13; } else { x14 = 0/*false*/; } x15 = x14; } else { x15 = 0/*false*/; } x16 = x15; } else { x16 = 0/*false*/; } return x16; } /*@ predicate match_any_w(char * x17) = (\exists integer x19; (((0<=x19) && (x19<strlen(x17))) && match_w((x17+x19))));*/ /*@ requires ((strlen(x31)>=0) && \valid(x31+(0..(strlen(x31)+1)-1))); assigns \nothing; ensures ((((\result ==> match_any_w(x31)) && (match_any_w(x31) ==> \result)) && ((!\result) ==> (!match_any_w(x31)))) && ((!match_any_w(x31)) ==> (!\result))); */ int matcher(char * x31) { int x33 = 0; int x34 = 0; /*@ loop invariant (((((((0<=x34) && (x34<=strlen(x31))) && (0<=x33)) && (x33<=5)) && ((strlen(x31)>=0) && \valid(x31+(0..(strlen(x31)+1)-1)))) && (\forall int x137; (((0<=x137) && (x137<(x34-x33))) ==> (!match_w((x31+x137)))))) && (((x33==1) ==> ((x34>=1) && (x31[(x34-1)]=='a'))) && (((x33==2) ==> ((x34>=2) && ((x31[(x34-2)]=='a') && (x31[(x34-1)]=='a')))) && (((x33==3) ==> ((x34>=3) && ((x31[(x34-3)]=='a') && ((x31[(x34-2)]=='a') && (x31[(x34-1)]=='b'))))) && (((x33==4) ==> ((x34>=4) && ((x31[(x34-4)]=='a') && ((x31[(x34-3)]=='a') && ((x31[(x34-2)]=='b') && (x31[(x34-1)]=='a')))))) && ((x33==5) ==> ((x34>=5) && ((x31[(x34-5)]=='a') && ((x31[(x34-4)]=='a') && ((x31[(x34-3)]=='b') && ((x31[(x34-2)]=='a') && (x31[(x34-1)]=='a')))))))))))); loop assigns x33, x34; loop variant ((((strlen(x31)*2)-(2*x34))+5)-x33); */ for (;;) { int x35 = x34; char x36 = x31[x35]; int x38 = x36 == '\0'; int x42; if (x38) { x42 = 0/*false*/; } else { int x39 = x33; int x40 = x39 < 5; x42 = x40; } if (!x42) break; int x44 = x33; int x45 = x44 == 0; if (x45) { int x46 = x34; char x47 = x31[x46]; int x48 = 'a' == x47; if (x48) { x33 += 1; x34 += 1; } else { x33 = 0; x34 += 1; } } else { int x57 = x44 == 1; if (x57) { int x58 = x34; char x59 = x31[x58]; int x60 = 'a' == x59; if (x60) { x33 += 1; x34 += 1; } else { x33 = 0; } } else { int x68 = x44 == 2; if (x68) { int x69 = x34; char x70 = x31[x69]; int x71 = 'b' == x70; if (x71) { x33 += 1; x34 += 1; } else { x33 = 1; } } else { int x79 = x44 == 3; if (x79) { int x80 = x34; char x81 = x31[x80]; int x82 = 'a' == x81; if (x82) { x33 += 1; x34 += 1; } else { x33 = 0; } } else { int x90 = x44 == 4; if (x90) { int x91 = x34; char x92 = x31[x91]; int x93 = 'a' == x92; if (x93) { x33 += 1; x34 += 1; } else { x33 = 1; } } else { } } } } } } int x288 = x33; int x289 = x288 == 5; return x289; }
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/*@ predicate sorted{L}(int* a, integer length) = \forall integer i,j; 0<=i<=j<length ==> a[i]<=a[j]; */ /*@ predicate swap{L1,L2}(int* a,integer i,integer j,integer length)= 0<=i<j<length && \at(a[i],L1) == \at(a[j],L2) && \at(a[i],L2) == \at(a[j],L1) && \forall integer k; 0<=k<length && k!=i && k!=j ==> \at(a[k],L1) == \at(a[k],L2); */ /*@ inductive same_elements{L1,L2}(int*a , integer length) { case refl{L}: \forall int*a, integer length; same_elements{L,L}(a,length); case swap{L1,L2}: \forall int*a, integer i,j,length; swap{L1,L2}(a,i,j,length) ==> same_elements{L1,L2}(a,length); case trans{L1,L2,L3}: \forall int*a, integer length; same_elements{L1,L2}(a,length) ==> same_elements{L2,L3}(a,length) ==> same_elements{L1,L3}(a,length); } */ /*@ requires \valid(a+(0..length-1)); requires length > 0; assigns a[0..length-1]; behavior sorted: ensures sorted(a,length); behavior same_elements: ensures same_elements{Pre,Here}(a,length); */ void sort (int* a, int length) { int current; /*@ loop invariant 0<=current<length; loop assigns a[0..length-1],current; for sorted: loop invariant sorted(a,current); for sorted: loop invariant \forall integer i,j; 0<=i<current<=j<length ==> a[i] <= a[j]; for same_elements: loop invariant same_elements{Pre,Here}(a,length); loop variant length-current; */ for (current = 0; current < length - 1; current++) { int min_idx = current; int min = a[current]; /*@ loop invariant current+1<=i<=length; loop assigns i,min,min_idx; loop invariant current<=min_idx<i; loop invariant a[min_idx] == min; for sorted: loop invariant \forall integer j; current<=j<i ==> min <= a[j]; loop variant length -i; */ for (int i = current + 1; i < length; i++) { if (a[i] < min) { min = a[i]; min_idx = i; } } if(min_idx != current) { L: a[min_idx]=a[current]; a[current]=min; /*@for same_elements:assert swap{L,Here}(a,current,min_idx,length);*/ } } }
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#include <limits.h> /*@ requires ((((((((0<x0) && (x0<100)) && (0<x1)) && (x1<100)) && (0<=x2)) && (0<=x3)) && (x2<x0)) && (x3<x1)); assigns \nothing; ensures ((0<=\result) && (\result<(x0*x1))); */ int index(int x0, int x1, int x2, int x3) { int x5 = x2 * x1; int x6 = x5 + x3; return x6; } /*@ predicate inv_matrix_Boolean(int * x26, integer x27, integer x28) = (((((x27<100) && (x28<100)) && (0<x27)) && (0<x28)) && (((x27*x28)>0) && \valid(x26+(0..(x27*x28)-1))));*/ /*@ requires (((((inv_matrix_Boolean(x63,x64,x65) && inv_matrix_Boolean(x66,x67,x68)) && inv_matrix_Boolean(x69,x70,x71)) && ((x70==x64) && (x71==x65))) && ((x70==x67) && (x71==x68))) && ((\forall int x121; (\forall int x122; ((((0<=x121) && (x121<(x70*x71))) && ((0<=x122) && (x122<(x64*x65)))) ==> \separated(x69+x121,x63+x122)))) && (\forall int x136; (\forall int x137; ((((0<=x136) && (x136<(x70*x71))) && ((0<=x137) && (x137<(x67*x68)))) ==> \separated(x69+x136,x66+x137)))))); ensures (((inv_matrix_Boolean(x63,x64,x65) && inv_matrix_Boolean(x66,x67,x68)) && inv_matrix_Boolean(x69,x70,x71)) && (\forall int x157; (((0<=x157) && (x157<(x70*x71))) ==> (x69[x157]==(x63[x157] || x66[x157]))))); */ void add(int * x63, int x64, int x65, int * x66, int x67, int x68, int * x69, int x70, int x71) { /*@assert \separated(x69+0,x63+0);*/ /*@assert \separated(x69+0,x66+0);*/ int x73 = x70 * x71; /*@ loop invariant 0<=x81<=x73; loop invariant (\forall int x82; (((0<=x82) && (x82<x81)) ==> (x69[x82]==(x63[x82] || x66[x82])))); loop assigns x81, x69[(0..x73-1)]; loop variant x73-x81; */ for(int x81=0; x81 < x73; x81++) { int x94 = x63[x81]; int x95 = x66[x81]; int x96 = x94 || x95; x69[x81] = x96; /*@assert \separated(x69+x81,x63+x81);*/ /*@assert \separated(x69+x81,x66+x81);*/ } } /*@ requires (((inv_matrix_Boolean(x172,x173,x174) && inv_matrix_Boolean(x175,x176,x177)) && ((x176==x173) && (x177==x174))) && (\forall int x213; (\forall int x214; ((((0<=x213) && (x213<(x176*x177))) && ((0<=x214) && (x214<(x173*x174)))) ==> \separated(x175+x213,x172+x214))))); ensures (((inv_matrix_Boolean(x172,x173,x174) && inv_matrix_Boolean(x175,x176,x177)) && (\forall int x233; (((0<=x233) && (x233<(x176*x177))) ==> (x175[x233]==(x171 && x172[x233]))))) && ((x171==\false) ==> (\forall int x247; (0<=x247<x176) ==> (\forall int x250; (0<=x250<x177) ==> (x175[((x247*x177)+x250)]==\false))))); */ void scalar_mult(int x171, int * x172, int x173, int x174, int * x175, int x176, int x177) { /*@assert \separated(x175+0,x172+0);*/ int x179 = x176 * x177; /*@ loop invariant 0<=x184<=x179; loop invariant (\forall int x185; (((0<=x185) && (x185<x184)) ==> (x175[x185]==(x171 && x172[x185])))); loop assigns x184, x175[(0..x179-1)]; loop variant x179-x184; */ for(int x184=0; x184 < x179; x184++) { int x197; if (x171) { int x196 = x172[x184]; x197 = x196; } else { x197 = 0/*false*/; } x175[x184] = x197; /*@assert \separated(x175+x184,x172+x184);*/ } }
54
/*@ requires n > 0; requires \forall int i; 0<= i <= n-1 ==> \valid(p + i); assigns \nothing; ensures \forall int i; 0 <= i <= n-1 ==> \result >= p[i]; ensures \exists int i; 0 <= i <= n-1 && \result == p[i]; */ int max_seq(int* p, int n); int max_seq(int* p, int n) { int res = *p; int i; /*@ ghost int idx = 0; */ /*@ loop invariant \forall integer j; 0 <= j <= i ==> res >= *(p+j); loop invariant \valid(p+idx) && *(p+idx) == res; */ for(i = 0; i < n; i++) { if (res < *p) { res = *p; /*@ ghost idx = i;*/ } p++; } return res; }
54
/*@ @ predicate canSee{L} (integer N, int *x, integer i) = @ \forall integer j; i < j < N ==> \at(x[i], L) > \at(x[j], L); @*/ /*@ @ predicate countTall{L} (integer N, int *x, integer i, integer c) = @ i >= N ? c == 0 : @ canSee{L}(N, x, i) ? countTall{L}(N, x, i + 1, c - 1) @ : countTall{L}(N, x, i + 1, c); @*/ /*@ @ requires N >= 1 && N <= 1000000; @ requires \valid (x + (0 .. N -1)); @ ensures \forall integer i; 0 <= i < N ==> x[i] == \old(x[i]); @ ensures countTall (N, x, 0, \result); @*/ int countWhoCanSee (int N, int x[]) { int tallest = x[N - 1]; int count = 1; /*@ @ loop invariant -1 <= i < N -1; @ loop invariant count + i <= N - 1; @ loop invariant \forall integer j; i < j < N ==> tallest >= x[j]; @ loop invariant \exists integer j; i < j < N && tallest == x[j]; @ loop invariant countTall (N, x, i + 1, count); @ loop assigns tallest, i, count; @ loop variant i + 1; @*/ for (int i = N - 2; i >= 0; --i) if (tallest < x[i]) { tallest = x[i]; count++; } return count; }
24
//binary search /*@ requires n>0; requires \valid_read(arr+(0..n-1)); requires val>0; behavior notfound: assumes \forall integer nf; 0<=nf<n ==> arr[nf]!= val; ensures \result == 0; behavior found: assumes \exists integer f; 0<=f<n && arr[f]==val; ensures \result == 1; complete behaviors; disjoint behaviors; */ int Linear(int arr[], int n, int val){ /*@ loop invariant 0<=i<=n; loop invariant \forall integer k; 0<=k<i ==> arr[k]!=val; loop assigns i; loop variant n-i; */ for(int i=0;i<n;i++){ if(val==arr[i]){ return 1; } } return 0; }
15
/*@ @ requires n > 0; @ requires \valid(a+(0..n - 1)); @ @ assigns \nothing; @ behavior okay_: @ assumes \exists int i; 0 <= i < n && a[i] == val; @ ensures 0 <= \result < n; @ ensures \forall int i; 0 <= i < \result ==> a[i] != val; @ ensures a[\result] == val; @ behavior not_okay_: @ assumes \forall int i; 0 <= i < n && a[i] != val; @ ensures \result == n; */ int find(int a[], int n, int val) { /*@ @ loop invariant 0 <= i <= n; @ loop invariant \forall int j; 0 <= j < i ==> a[j] != val; @ loop variant n - i; */ for (int i = 0; i < n; ++i) { if (a[i] == val) return i; } return n; }
15
/*@ requires \valid(a + (0..n-1)); assigns a[0..n]; // should be a[0..n-1] */ void foo(int* a, unsigned int n) { /*@ loop invariant 0 <= i <= n; loop assigns i, a[0..n]; // should be a[0..n-1]; loop variant n-i; */ for(unsigned int i = 0; i < n; ++i) a[i] = 0; }
11
/*@ requires n > 0; requires \forall integer i,j; 0 <= i <= j <= n-1 ==> a[i] <= a[j]; requires \valid_read(a + (0..n-1)); ensures (\forall integer k; 0 <= k <= n-1 ==> a[k] != x) || x == a[\result]; assigns \nothing; */ int binarysearch(int* a, int x, int n) { int low = -1; int high = n; int p; /*@ loop invariant \forall integer i,j; 0 <= i <= j <= n-1 ==> a[i] <= a[j]; loop invariant \forall integer k; 0 <= k <= low ==> a[k] < x; loop invariant \forall integer k; high <= k <= n-1 ==> a[k] > x; loop invariant -1 <= low+1 <= high <= n; loop assigns low, high, p; */ while (low+1 < high) { p = (low + high) / 2; if (a[p] == x) return p; else if (a[p] < x) low = p; else high = p; } return -1; }
11
#include <limits.h> #include <string.h> /*@ requires ((strlen(x0)>=0) && \valid(x0+(0..strlen(x0)))); */ int matcher_a_end(char * x0) { int x2 = 0/*false*/; int x3 = 1/*true*/; char *x4 = x0; /*@ loop invariant ((strlen(x4)>=0) && \valid(x4+(0..strlen(x4)))); loop assigns x2, x3, x4; loop variant ((strlen(x4)+((x2) ? (0) : (1)))+((x3) ? (1) : (0))); */ for (;;) { int x5 = x2; int x9; if (x5) { x9 = 0/*false*/; } else { int x7 = x3; x9 = x7; } if (!x9) break; char *x11 = x4; char x12 = x11[0]; int x13 = x12 == '\0'; int x16; if (x13) { x16 = 0/*false*/; } else { int x15 = 'a' == x12; x16 = x15; } int x20; if (x16) { char *x17 = x11+1; char x18 = x17[0]; int x19 = x18 == '\0'; x20 = x19; } else { x20 = 0/*false*/; } x2 = x20; int x22 = x2; if (x22) { } else { int x14 = !x13; x3 = x14; int x25 = x3; if (x25) { char *x17 = x11+1; x4 = x17; } else { } } } int x56 = x2; return x56; }
15
/* run.config EXECNOW: make tests/aorai/Aorai_test.cmxs OPT: -aorai-ltl tests/aorai/goto.ltl -aorai-test 1 -aorai-acceptance -load-module tests/aorai/Aorai_test.cmxs -aorai-test-number @PTEST_NUMBER@ */ int status=0; int rr=1; //@ global invariant inv : 0<=rr<=5000; /*@ requires rr<5000; @ behavior j : @ ensures rr<5001; */ void opa() { rr++; } void opb () { status=1; } void opc () { rr=60000; } int main(){ if (rr<5000) goto L; opc(); L4: goto L5; L: opa(); goto L2; opc(); L6: return 1; L3: goto L4; opc(); goto L2; L2 : goto L3; L5: opb(); goto L6; }
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/*@ requires 0<=first<=180 && 0<=second<=180; ensures \result + first + second == 180; */ int last_angle(int first,int second){ return 180 - first - second; }
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#include <limits.h> /*@ requires (x0<INT_MAX); assigns \nothing; ensures (\result>x0); */ int inc(int x0) { int x2 = x0 + 1; return x2; }
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#include <limits.h> #include <string.h> /*@ requires ((strlen(x0)>=0) && \valid(x0+(0..strlen(x0)))); */ int matcher_a(char * x0) { int x2 = 0/*false*/; int x3 = 1/*true*/; char *x4 = x0; /*@ loop invariant ((strlen(x4)>=0) && \valid(x4+(0..strlen(x4)))); loop assigns x2, x3, x4; loop variant ((strlen(x4)+((x2) ? (0) : (1)))+((x3) ? (1) : (0))); */ for (;;) { int x5 = x2; int x9; if (x5) { x9 = 0/*false*/; } else { int x7 = x3; x9 = x7; } if (!x9) break; char *x11 = x4; char x12 = x11[0]; int x13 = x12 == '\0'; int x16; if (x13) { x16 = 0/*false*/; } else { int x15 = 'a' == x12; x16 = x15; } int x18; if (x16) { x18 = 1/*true*/; } else { x18 = 0/*false*/; } x2 = x18; int x20 = x2; if (x20) { } else { int x14 = !x13; x3 = x14; int x23 = x3; if (x23) { char *x17 = x11+1; x4 = x17; } else { } } } int x54 = x2; return x54; }
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#include <stdio.h> /*@ requires a >= 0 && b > 0; @ requires \valid(r); @ assigns *r; @ ensures a == b * \result + *r; */ int idiv(int a, int b, int *r) { int q = 0; int p = a; /*@ assert a == b * q + p;*/ /*@ loop invariant a == b * q + p; @ loop assigns q, p; @ loop variant p; */ while (p >= b) { q++; p -= b; } *r = p; return q; } /* int main(int argc, char** argv) { int r = 0; int q = idiv(5, 2, &r); printf("q=%d, r=%d\n", q,r ); return 0; }*/
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